Answer:
We conclude that the true mean weight is not 28.3 grams at 5% significance level.
Step-by-step explanation:
We are given that some students checked 6 bags of Doritos marked with a net weight of 28.3 grams.
They carefully weighed the contents of each bag, recording the following weights (in grams): 29.2, 28.5, 28.7, 28.9, 29.1, 29.5. The average weight is 29.0 and the standard deviation is 0.36.
Let [tex]\mu[/tex] = true mean weight of bag.
So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 28.3 grams {means that the true mean weight is 28.3 grams}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] [tex]\neq[/tex] 28.3 grams {means that the true mean weight is not 28.3 grams}
The test statistics that would be used here One-sample t test statistics as we don't know about the population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean weight = 29.0 grams
s = sample standard deviation = 0.36 grams
n = sample of bags = 6
So, test statistics = [tex]\frac{29.0-28.3}{\frac{0.36}{\sqrt{6} } }[/tex] ~ [tex]t_5[/tex]
= 4.763
The value of t test statistics is 4.763.
Since, in the question we are not given the level of significance so we assume it to be 5%. Now, at 5% significance level the t table gives critical values of -2.571 and 2.571 at 5 degree of freedom for two-tailed test.
Since our test statistics does not lie within the range of critical values of t, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.
Therefore, we conclude that the true mean weight is not 28.3 grams.
There is strong evidence to suggest that the true mean weight of the Doritos bags is not 28.3 grams, based on a hypothesis test that resulted in a very low p-value.
To determine if there is strong evidence that the true mean weight of the Doritos bags is not 28.3 grams, we perform a hypothesis test using the given data.
State the null hypothesis (H0) and the alternative hypothesis (Ha):
H0: μ = 28.3 grams (the true mean weight is 28.3 grams)
Ha: μ ≠ 28.3 grams (the true mean weight is not 28.3 grams)
Calculate the test statistic:
The test statistic for a sample mean is given by:
z = (sample mean - population mean) / (standard deviation / √(n))
Here, the sample mean = 29.0 grams, population mean = 28.3 grams, standard deviation = 0.36 grams, and n = 6.
Thus, z = (29.0 - 28.3) / (0.36 / √(6)) ≈ 4.08
Using a z-table, the p-value associated with a z-score of 4.08 is extremely small (much less than 0.05).
Compare the p-value to the significance level (α):
At α = 0.05, since the p-value is much smaller, we reject the null hypothesis.
Since the p-value is very low, there is strong evidence to suggest that the true mean weight of the Doritos bags is not 28.3 grams.
An SAT coaching company claims it's course can raise SAT scores of high school students (thus, when they take it a second time after being coached). Of course, students who retake the SAT without paying for coaching generally raise their scores also. A random sample of students who took the SAT twice found 427 who were coached and 2733 who were not coached. For both the coached group and the uncoached group, the gain in score was recorded. The SAT coaching company wishes to test to see if their coaching provided better second attempts on average. What case is best
Answer:
Check the explanation
Step-by-step explanation:
(a) The appropriate test is the matched-pairs test because a student’s score on Try 1 is certainly correlated with his/her score on Try 2. Using the differences, we have xbar = 29 and s = 59.
(b) To test H0: mu=0 vs. H1 mu > 0, we compute
[tex]t = (29-0)/((59/sqrt(427))=10.16[/tex]
with df = 426. This is certainly significant, with P < 0.0005. Coached students do improve their scores on average
(a) H0: μ1 = μ2 vs. Ha: μ1 > μ2, where μ1 is the mean gain among all coached students and μ2 is the mean gain among uncoached students. H0 and Ha. Using the conservative approach, df = 426 is rounded down to df = 100 in (t table) and we obtain 0.0025 < P < 0.005. Using software, df = 534.45 and P = 0.004. There is evidence that coached students had a greater average increase.
(b) 8 ± t*(3.0235) where t* equals 2.626 (using df = 100 with (t table) ) or 2.585 (df = 534.45 with software). This gives either 0.06 to 15.94 points, or 0.184 to 15.816 points, respectively.
(c) Increasing one’s score by 0 to 16 points is not likely to make a difference in being granted admission or scholarships from any colleges.
A marketing research company needs to estimate which of two medical plans its employees prefer. A random sample of n employees produced the 95% confidence interval (0.366 comma 0.506 )for the proportion of employees who prefer plan A. Identify the point estimate for estimating the true proportion of employees who prefer that plan.
Answer:
The point estimate for estimating the true proportion of employees who prefer that plan is 0.436
Step-by-step explanation:
A confidence interval has two bounds, a lower bound and an upper bound.
A confidence interval is symmetric, which means that the point estimate used is the mid point between these two bounds, that is, the mean of the two bounds.
In this problem, we have that:
Lower bound: 0.366
Upper bound: 0.506
Point estimate:
(0.366 + 0.506)/2 = 0.436
The point estimate for estimating the true proportion of employees who prefer that plan is 0.436
Answer:
[tex]\hat p = \frac{0.366+0.506}{2}= 0.436[/tex]
And the point of estimate for the proportion of employees who prefer plan is on this case 0.436 or 43.6%.
Step-by-step explanation:
We define the parameter of interest as the proportion of employees who prefer plan p and we want to estimate this true parameter
The confidence interval for the this proportion is given by the following formula:
[tex]\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}[/tex]
After calculate the 95% confidence interval we got (0.366, 0.506)
We can obtain the best estimate for the proportion of employees who prefer plan like this:
[tex]\hat p =\frac{Upper +Lower}{2}[/tex]
Where Upper and Lower represent the limits for the confidence interval and replacing we got:
[tex]\hat p = \frac{0.366+0.506}{2}= 0.436[/tex]
And the point of estimate for the proportion of employees who prefer plan is on this case 0.436 or 43.6%.
The margin of error can be estimated using the fact that this confidence interval is symmetrical and we got:
[tex]ME=\frac{Upper-Lower}{2}= \frac{0.506-0.366}{2}=0.07[/tex]
Compensation professionals in XYZ Company use regression analysis to determine the pay rates of its marketing professionals. There are 4 different marketing job titles in XYZ Company. Compensation professionals use job evaluation points assigned to each marketing job title and a salary survey data. In other words, they regress job evaluation points on the salary data. What does it mean when the R2 value of this regression turns out to be 0.85
Answer: This means that the salaries of their marketing professionals are not closely related to their job titles. In further explanation, this shows that a professional with a higher job title, may be paid a lower salary when compared to a professional with a lower job title.
A 0.85 R-Squared shows that the points are far from the trend lines. From this, we can assume that the marketing professionals are paid base on commission on sales, and not base on job position.
Step-by-step explanation: R-Squared is a measure used in statistics, to represent how much proportion of the dependent variables that is explained by the independent variables. A high value of R^2 shows a very low correlation between the dependent and independent variables, while a low value of R^2 shows that the dependent and independent variables are closely related. The R-Squared value are a measure of percentage value.
What is the volume of the prism? Length 8ft height 12ft width 6ft
Answer:
[tex]\huge\boxed{V=576\ ft^3}[/tex]
Step-by-step explanation:
[tex]\text{The formula of a volume of a prism with dimensions}\ l\times w\times h:\\\\V=lwh.\\\\\text{We have}\\\\l=8ft,\ w=6ft,\ h=12ft.\\\\\text{Substitute:}\\\\V=(8)(6)(12)=576(ft^3)[/tex]
Ella already knew 5 appetizer recipes before starting culinary school, and she will learn 2 new
appetizer recipes during each week of school. Write an equation that shows the relationship
between the number of weeks w and the number of appetizer recipes a.
Write your answer as an equation with a first, followed by an equals sign.
A = 2w+5
example: on week three, she would have the recipes from the other weeks that you have to account for as well as the extra five
2(3)+5=11 so A would equal 11 by week three.
Use multiplication because it is essentially repeated addition.
2(from week 1) + 2(from week 2) + 2(from week 3) + 5(prior to school) =11
What are the roots of the polynomial equation?
Answer:
The roots of the polynomial equation in this case would be the intersection of the 2 polynomial functions. which are at x = 4 and x = -3
Step-by-step explanation:
The roots are found by finding the x-values of the intersections of these two cubic polynomial functions.
We could try solving algebraically, but you have the graph.
The bottom of a ladder must be placed 5 feet from the building. The ladder is 14 feet long. How far above the ground does the ladder touch the wall?
Answer:
3 square roots of 19
Step-by-step explanation:
a squared + b squared = c squared
5 squared + b squared = 14 squared
25 + b squared = 196 squared
b squared = 171
b = square root of 171
b = 3 square roots of 19
hi
If your wall is straight , then. you have a rectangular traingle.
As Pythagoras tells us : wall² = ladder²- ground distance²
wall² = 14²- 5²
wall² = 196 -25
wall² = √171≈13,07
Rebecca said that the graph is NOT a function. What is the BEST reason she could give to Mr. Bradley to support her statement?
A) The graph is not symmetrical about the y-axis
B) Every value of y has a single value of x
C) A vertical line placed on the graph could intersect more than one point
D) Every value of x has a single value of y
Answer:
choose choice C.
Step-by-step explanation:
many vertical lines can cross this graph more than once, which defies the definition of a function.
Answer:
c) A vertical line placed on the graph could intersect more than one point
Step-by-step explanation:
if you did the vertical line test, you would see that there would be more than one point per value.
hope i helped:) !!!
brainliest ??
Patricia got a 5/25 balloon mortgage and her initial payments were $965. She
decided to refinance her balloon payment with a 30-year mortgage and her
new payments were $925. What is the total financed cost she paid for her
house?
Answer:
$390,900
Step-by-step explanation:
Given:
Initial payment = $965
New rapayment = $925 when she decided to refinance her ballon payment with a 30 year mortgage
In this case, a 5/25 ballon mortgage simply means loan repayment for the first 5 years is at a fixed rate.
Which means the total amount she paid in the first five years was=
12 * 5 * $965 = $57,900
When she refinanced the payment with a 30 year mortgage, her total payment = $925 * 12 * 30years = $333,000
Total financed cost Patricia paid =
$57,900 + $333,000 = $390,900
If the height of the parallelogram shown is decreased by 1 inch and the base is decreased by 2 inches, what is the area of the new parallelogram?
a. 108in2
b. 104in2
c. 78in2
d. 84 in2
Answer:
B
Step-by-step explanation:
you multiply the numbers and remember the little square is 90
The area of new parallelogram is 78in2
The original parallelogram has a base of 18 inches and a height of 10 inches. Therefore, its area is 18 x10 = 180 square inches.If the height is decreased by 1 inch and the base is decreased by 2 inches, the new base will be 18 - 2 = 16 inches and the new height will be 10 - 1 = 9 inches. So, the area of the new parallelogram will be 16 x 9 = 144 square inches.Therefore, the answer is c. 78in2.
Here's a breakdown of the reasoning for each option:a. 108in2: This is incorrect because it's smaller than the area of the original parallelogram, even though both the base and height are decreased.b. 104in2:
This is also incorrect because it's still larger than the area of the new parallelogram.c. 78in2:
This is the correct answer, as calculated above.d. 84 in2: This is incorrect because it's closer to the area of the original parallelogram than the new one.
What is the surface area
Suppose that you found two different solutions for a system of two linear equations. How many solutions must the system have?
Answer:
One solution.
Step-by-step explanation:
A linear line only goes one way, and thus, two lines can only meet at one point.
That is unless, the linear equations are both the same, then they will have infinite solutions.
But what you're asking is if they're different so no, you cannot have two solutions for a system of two linear equations.
Answer:
0
Step-by-step explanation:
Two different solutions means the two equations aren't consistent - there's no unique solution that solves the whole system. Two lines can meet at at most one point, so in this case, no solution to the first equation will be a solution to the second. The system has 0 solutions.
Find the measures of angels of M and N
M (6y-10)
N (4y-10)
We have been given an image of a trapezoid. We are asked to find the measure of angle M and N.
We know that bases of trapezoid are parallel and the two angles between two parallel lines are supplementary, so we can set an equation as:
[tex]\angle M+\angle N=180[/tex]
[tex](6y-10)+(4y-10)=180[/tex]
[tex]6y-10+4y-10=180[/tex]
[tex]10y-20=180[/tex]
[tex]10y-20+20=180+20[/tex]
[tex]10y=200[/tex]
[tex]\frac{10y}{10}=\frac{200}{10}[/tex]
[tex]y=20[/tex]
Upon substituting value of y in measure of angle M, we will get:
[tex]m\angle M=6y-10[/tex]
[tex]m\angle M=6(20)-10[/tex]
[tex]m\angle M=120-10[/tex]
[tex]m\angle M=110[/tex]
Therefore, measure of angle M is 110 degrees.
Similarly, we will find the value of angle N as:
[tex]m\angle N=4y-10[/tex]
[tex]m\angle N=4(20)-10[/tex]
[tex]m\angle N=80-10[/tex]
[tex]m\angle N=70[/tex]
Therefore, measure of angle N is 70 degrees.
Help! Best answer = Brainiest!
The point M(-6,8) is the midpoint of AB. The point A has coordinates (-2,10). What are the coordinates of B
Answer:
m/6-8 =m/58
Step-by-step explanation:
Using the midpoint formula, the coordinates of point B are determined by setting up equations with the known coordinates of point A and midpoint M. Solving these equations yields the x-coordinate of B as -10 and the y-coordinate as 6, making the coordinates of point B (-10, 6).
Explanation:The question is asking to determine the coordinates of point B if M(-6,8) is the midpoint of AB and A has coordinates (-2,10). To find the coordinates of B, we use the midpoint formula which states that the midpoint M(x,y) is given by M = ((x1 + x2)/2, (y1 + y2)/2) where (x1, y1) and (x2, y2) are the coordinates of points A and B respectively. Since we know the coordinates of A and M, we can set up equations to solve for the coordinates of B.
To find the x-coordinate of B, we set up the equation -6 = (-2 + xB)/2 which yields xB = -10. For the y-coordinate, we use the equation 8 = (10 + yB)/2 which gives us yB = 6. Therefore, the coordinates of point B are (-10, 6).
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34. The sum of the lengths of the two bases of a trapezoid
is 22 cm, and its area is 66 cm". What is the height of
the trapezoid?
Answer:
h=6
Step-by-step explanation:
the formula for a trapezoid’s area is to multiply the bases (a and b) by the height of the trapezoid, then divide it all by 2.
so typed out, that would look like:
((a+b) h) / 2
and in the case of this problem:
((22) h) / 2 = 66
so just go ahead and solve it algebraically from there and you’re good!
what is the value of 6+ {[3x(13-5)]-2}
Answer:
28 you have to do it from left to right
Answer:
13-5=8
3x8=24
24-2=22
22+6=28
28 is your answer
Step-by-step explanation:
Find the distance between (3, 24) and (7,
56).
Answer:
Square root of 1040
Decimal form - 32.249
Step-by-step explanation:
The distance between the endpoints (3, 24) and (7, 56) will be 32.25 units.
What is the distance between two points?Let one point be (x, y) and another point be (h, k).
Then the distance between the points will be
D² = (x - h)² + (y - k)²
The two endpoints are given below.
(3, 24) and (7, 56)
Then the distance between the endpoints (3, 24) and (7, 56) will be
D² = (7 - 3)² + (56 - 24)²
D² = 4² + 32²
D² = 16 + 1024
D² = 1040
D = 32.25 units
The distance between the endpoints (3, 24) and (7, 56) will be 32.25 units.
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answer question pls
Answer:
B,1/5
Step-by-step explanation:
Answer:
the answer would be
B aka your second option
Step-by-step explanation:
i don't really have a step by step but this is the first question i've answered on this app let me know if i am helpful!!
Simplify: (−7x + 5) – (2x2 – 8x + 6)
Answer:
2x^2 + x -1
Step-by-step explanation:
-7x + 5 - 2x^2 + 8x -6
2x^2 + x -1
Which dot plot shows a sample that is most representative of the number of pets in a household?
THE COMPLETE QUESTION IS:
Which dot plot shows a sample that is most representative of the number of pets in a household?
A. A dot plot going from 0 to 6. There are 3 dots above 0, 5 dots above 1, 4 dots above 2, 3 dots above 3, 2 dots above 4, 0 dots above 5, and 1 dot above 6.
B. Adot plot going from 0 to 6. There are 2 dots above 1, 3 dots above 2, and 1 dot above 5.
C. A dot plot going from 0 to 6. There is 1 dot above 0, 2 dots above 1, 1 dot above 2, 1 dot above 3, 1 dot above 4, 1 dot above 5, 2 dots above 6.
D. A dot plot going from 0 to 6. There is 1 dot above 1, 2 dots above 2, 3 dots above 3, 2 dots above 4, 1 dot above 5.
Answer:
A is the correct option
Step-by-step explanation:
A. A dot plot going from 0 to 6. There are 3 dots above 0, 5 dots above 1, 4 dots above 2, 3 dots above 3, 2 dots above 4, 0 dots above 5, and 1 dot above 6.
A has 3+5+4+3+2+0+1 = 18 dots
The rest are not up to 18.
The best graphical representation of the number of pets in a household is: A dot plot going from 0 to 6. There are 3 dots above 0, 5 dots above 1, 4 dots above 2, 3 dots above 3, 2 dots above 4, 0 dots above 5, and 1 dot above 6.
What is a graph?A graph can be defined as the graphical representation of data (information) on both the horizontal and vertical lines, which are commonly called the x-axis and y-axis respectively.
The types of graph.In Mathematics, there are different types of graph and these include:
Scatter plotBar graphPie chartDot plot.A dot plot refers to a type of graph which comprises small data points that are plotted on a simple histogram-like graph. Thus, the number of pets in a household should be represented by using a dot plot with its value ranging from 0 to 6.
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The parent function f(x) = 1.5x is translated such that the function g(x) = 1.5x + 1 + 2 represents the new function. Which is the graph of g(x)? On a coordinate plane, an exponential function increases from quadrant 2 to quadrant 1. It crosses the y -axis at (0, 2.5). On a coordinate plane, an exponential function increases from quadrant 3, through quadrant 4, to quadrant 1. It crosses the y-axis at (0, negative 0.5). On a coordinate plane, an exponential function increases from quadrant 3, through quadrant 4, to quadrant 1. It crosses the y-axis at (0, negative 1.5). On a coordinate plane, an exponential function increases from quadrant 2 to quadrant 1. It crosses the y -axis at (0, 3.5).
Answer:
Its the fourth graph
Step-by-step explanation:
i got it right
Answer: the 4th one
Step-by-step explanation:
i just did this
31) Carter Motor Company claims that its new sedan, the Libra, will average better than 32 miles per gallon in the city. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is to reject the null hypothesis, state the conclusion in nontechnical terms. a. There is not sufficient evidence to support the claim that the mean is greater than 32 miles per gallon. b. There is not sufficient evidence to support the claim that the mean is less than 32 miles per gallon. c. There is sufficient evidence to support the claim that the mean is less than 32 miles per gallon. d. There is sufficient evidence to support the claim that the mean is greater than 32 miles per gallon.
Answer:
Option D is correct.
Rejecting the null hypothesis means that;
There is sufficient evidence to support the claim that the mean is greater than 32 miles per gallon.
Step-by-step explanation:
For hypothesis testing, the first thing to define is the null and alternative hypothesis.
In hypothesis testing, especially one comparing two sets of data, the null hypothesis plays the devil's advocate and usually takes the form of the opposite of the theory to be tested. It usually contains the signs =, ≤ and ≥ depending on the directions of the test. It usually maintains that, with random chance responsible for the outcome or results of any experimental study/hypothesis testing, its statement is true.
The alternative hypothesis usually confirms the theory being tested by the experimental setup. It usually contains the signs ≠, < and > depending on the directions of the test. It usually maintains that significant factors other than random chance, affect the outcome or results of the experimental study/hypothesis testing and result in its own statement.
For this question, Carter Motor Company claims that its new sedan, the Libra, will average better than 32 miles per gallon in the city. And since this is talking distance covered per gallon of fuel, better means that the new sedan will average more than 32 miles per gallon.
So, the null hypothesis negating this claim would be that there isn't significant evidence to conclude that the average of the new sedan will be better or greater than 32 miles per gallon.
That is, the new average will be less than or equal to 32 miles per hour.
And the alternative hypothesis will confirm the claim that there is significant evidence to conclude that the average of the new sedan will be better or greater than 32 miles per gallon.
Mathematically,
The null hypothesis is represented as
H₀: μ ≤ 32 miles per gallon
The alternative hypothesis is given as
Hₐ: μ > 32 miles per gallon
So, after the hypothesis test has been conducted, rejecting the null hypothesis means accepting the alternative hypothesis and its statement that there is significant evidence to conclude that the average of the new sedan will be better or greater than 32 miles per gallon.
Hence, option D is correct.
Hope this Helps!!!
The conclusion of the hypothesis test indicates that there is sufficient evidence to support the claim that the mean fuel efficiency of the new Libra sedan is greater than 32 miles per gallon.
Explanation:From the noun hypothesis testing conducted, the conclusion drawn is to reject the null hypothesis. In non-technical terms, rejecting the null hypothesis means that based on the data collected and analyzed, there is sufficient statistical evidence to support the claim that contrary to the null hypothesis, the average (or 'mean') miles per gallon of the new Libra sedan is indeed greater than 32 miles per gallon. These results should confirm Carter Motor Company's assertions about their vehicle's fuel efficiency.
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Which of the following statements is false?
a. R3 is a vector space
b. P2 is a vector space
C. M2x2 is a vector space
d. The set of all polynomials of degree 4 is a vector space
Answer:
C . M2x2 is a vector space
Step-by-step explanation:
According to the definition, the each element in a vector spaces is a vector. So, 2×2 matrix cannot be element in a vector space since it is not even a vector.
The set of all ordered triples of real numbers is called 3‐space, denoted R 3 (“R three”). See Figure . ... Vectors in R 3 are called 3‐vectors (because there are 3 components), and the geometric descriptions of addition and scalar multiplication given for 2‐vectors also carry over to 3‐vectors.
Since every polynomial of degree up to 2 is also a polynomial of degree up to 3, P2 is a subset of P3. And we already know that P2 is a vector space, so it is a subspace of P3.
With addition, the set of polynomials of degree 2 almost form a vector space, but there are some problem. The first one, is that the zero vector, i.e. the zero polynomial is not of degree 2. ... If you really need them to form a vector space, then you should consider the set of all polynomials of degree at most 2.
For the data set 2.5, 6.5, 9, 19, 20, 2.5 what is the mean absolute deviation
Answer:
9
Step-by-step explanation:
it's 9 because you always look in the middle for the mean
Line x and line z are straight lines. Lines x, z, and y intersect to form 5 angles. From top left, clockwise, the angles are: a: right angle, b, c, d, e. Which pair of angles are vertical? Angle a and Angle d Angle b and Angle d Angle a and Angle b Angle c and Angle e
Answer: C AND E
Step-by-step explanation:
Option D is correct, Angle c and Angle e are vertical angles.
What is Trigonometry?Trigonometry is a branch of mathematics that studies relationships between side lengths and angles of triangles.
Given that Line x and line z are straight lines.
Lines x, z, and y intersect to form 5 angles. From top left, clockwise, the angles are: a: right angle, b, c, d, e.
Vertical angles are opposite to each other and not adjacent.
In this case, angle c and angle e are opposite to each other, as they are on opposite sides of the intersection between lines y and z, and they are not adjacent to each other. Therefore, they must be vertical angles.
Hence, Option D is correct, Angle c and Angle e are vertical angles.
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A roof on a castle tower is shaped like a cone with a diameter of 12 feet and has a slant height of 13 feet one bundle of Shingles covers 32 ft.² how many bundles should you buy to cover the roof
Answer:
8
Step-by-step explanation:
The lateral area of a cone is ...
LA = (π/2)ds
where d is the diameter, and s is the slant height.
The area of this tower roof is about ...
LA = (π/2)(12 ft)(13 ft) = 78π ft² ≈ 245 ft²
About 245/32 = 7.7 bundles of shingles will be required for coverage.
You should buy 8 bundles of shingles to cover the roof.
© If you take a number, times by 7 then subtract 1. You get the same as if you took the number,
times by 5 then subtract 8. What is the number?
Answer:
-7/2
Step-by-step explanation:
This question is a word problem.
Step 1: interpretation the question
Let's assume the number is x;
X×7 – 1 = X×5 – 8
7x - 1 = 5x - 8
Step 2. Solve the equation for the unknown.
7x - 1 = 5x - 8
Take like terms together
7x - 5x = - 8 +1
2x = -7
Divide both sides by 2
x = -7/2
The answer is -7/2
En un platillo de una balanza colocamos un queso, en el otro ponemos las tres cuartas partes de otro queso igual y para equilibrarlo añadimos un peso de tres cuartos de kilo. ¿Cuál es el peso del queso?
Answer: The cheese weighs 3 kilograms.
Step-by-step explanation:
I will answer this in English, feel free to translate it if you need it.
This can be translated to:
In a weighing pan of a scale, we place a cheese, in the other we put three-quarters of another cheese equal, and to balance it we add a weight of 3/4 kg. What is the weight of the cheese?
We know that the weight on both pans must be the same.
Then if the weight of the cheese is C, we have the equation:
C = (3/4)*C + 3/4kg
this says:
The weight of the complete cheese is equal to the weight of 3/4 of the cheese plus 3/4kg.
Now we can solve it for C.
C - (3/4)*C = 3/4kg
C*(1 - 3/4) = C*(1/4) = 3/4kg
C = 4*(3/4)kg = 3kg
The cheese weighs 3 kilograms.
Our environment is very sensitive to the amount of ozone in the upper atmosphere. The level of ozone normally found is 7.8 parts/million (ppm). A researcher believes that the current ozone level is not at a normal level. The mean of 16 samples is 8.2 ppm with a standard deviation of 0.6. Assume the population is normally distributed. A level of significance of 0.01 will be used. Find the value of the test statistic. Round your answer to two decimal places.
Answer:
The value of the test statistic is [tex]t = 2.67[/tex]
Step-by-step explanation:
The null hypothesis is:
[tex]H_{0} = 7.8[/tex]
The alternate hypotesis is:
[tex]H_{1} \neq 7.8[/tex]
Our test statistic is:
[tex]t = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.
In this problem, we have that:
[tex]X = 8.2, \mu = 7.8, \sigma = 0.6, n = 16[/tex]
Then
[tex]t = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]t = \frac{8.2 - 7.8}{\frac{0.6}{\sqrt{16}}}[/tex]
[tex]t = 2.67[/tex]
The value of the test statistic is [tex]t = 2.67[/tex]