To find the length of the band holding four pencils together, calculate the circumference of each pencil using the formula C = 2πr, where C is the circumference and r is the radius. Multiply the circumference of each pencil by 4 to find the total length of the band.
Explanation:To find the length of the band holding four pencils together, you need to calculate the circumference of the pencils. The diameter of each pencil is given as 10 mm, so the radius is half of the diameter, which is 5 mm. The formula for calculating the circumference of a circle is C = 2πr, where C is the circumference, π is a constant approximately equal to 3.14159, and r is the radius. Therefore, the circumference of each pencil is 2π(5 mm) = 10π mm. Since there are four pencils, the total length of the band is 10π mm x 4 = 40π mm. This is your answer in terms of π.
Probability. Help! I'll give you Brainliest if correct as well as quite a bit of points.
A card is chosen at random from a standard deck of 52 cards, and then it is replaced and another card is chosen. What is the probability that at least one of the cards is a diamond or an ace?
Answer:
17/52
Step-by-step explanation:
there are 13 diamonds in a standard deck of 52 cards.
the probability of getting a diamond will therefore be 13/52 = 1/4
there are 4 aces in a standard deck of 52 cards.
the probability of getting an ace will therefore be 4/52 = 1/13
the probability of getting a diamond or an ace will be 1/4 + 1/13
= 17/52
During a walk a thin Noah’s time in hours, t, and distance in miles, d, are related by the equation 1/3d = t. A graph of the equation includes the point (12, 4)
1. Identify the independent variable
2. What does the point (12, 4) represent in this situation
3. What point would represent the time it too to walk 7 1/2 miles
Answer:
Step-by-step explanation:
The independent variable is time (t), determining the distance covered.
The point (12, 4) means Noah walks for 12 hours, covering 4 miles.
To find time for 7[tex]\frac{1}{2}[/tex] miles, [tex]\frac{1}{3}d = t \),[/tex] Substitute 7.5 for d, yielding [tex]\( \frac{1}{3} 7.5 = t \) = 2.5 hour[/tex]. So, (2.5, 7.5) represents Noah taking 2.5 hours to walk 7[tex]\frac{1}{2}[/tex] miles.
1. **Identify the independent variable**:
In the equation [tex]\( \frac{1}{3}d = t \),[/tex] the independent variable is time (t). The independent variable is the one that stands alone and is not dependent on other variables. In this case, time (t) is independent as it determines the distance covered (d).
2. **What does the point (12, 4) represent in this situation**:
The point (12, 4) represents a specific instance in the relationship between time and distance. In this case, it means that when Noah walks for 12 hours, he covers a distance of 4 miles. This point is a solution to the equation [tex]\( \frac{1}{3}d = t \),[/tex] where 12 hours corresponds to the time (t) and 4 miles corresponds to the distance (d).
3. **What point would represent the time it took to walk 7 1/2 miles**:
To find the point representing the time it takes to walk 7 1/2 miles, we substitute 7.5 miles into the equation and solve for time (t). First, we rewrite the equation without fractions to make the calculation simpler:
[tex]\[ \frac{1}{3}d = t \][/tex]
[tex]\[ \frac{1}{3} \times d = t \][/tex]
[tex]\[ \frac{1}{3} \times 7.5 = t \][/tex]
Now, we simply multiply 1/3 by 7.5:
[tex]\[ t = \frac{1}{3} \times 7.5 \][/tex]
[tex]\[ t = 2.5 \][/tex]
So, the time it takes to walk 7[tex]\frac{1}{2}[/tex] miles is 2.5 hours. Therefore, the point representing this situation is (2.5, 7.5), indicating Noah takes 2.5 hours to walk 7.5 miles. This point satisfies the equation [tex]\( \frac{1}{3}d = t \)[/tex], where 2.5 hours corresponds to the time (t) and 7.5 miles corresponds to the distance (d).
In summary, the independent variable in this situation is time (t), the point (12, 4) represents Noah walking for 12 hours and covering 4 miles, and the point (2.5, 7.5) represents Noah taking 2.5 hours to walk 7[tex]\frac{1}{2}[/tex] miles.
At a tennis tournament a statistician keeps track of every serve. The statistician reported that the mean serve speed of a particular player was 101 miles per hour (mph) and the standard deviation of the serve speeds was 15 mph. Assume that the statistician also gave us the information that the distribution of the serve speeds was bell shaped. What proportion of the player's serves are expected to be between 116 mph and 146 mph? Round to four decimal places.
Answer:
0.1574 = 15.74% of the player's serves are expected to be between 116 mph and 146 mph
Step-by-step explanation:
Problems of normally distributed(bell-shaped) samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:
[tex]\mu = 101, \sigma = 15[/tex]
What proportion of the player's serves are expected to be between 116 mph and 146 mph?
This is the pvalue of Z when X = 146 subtracted by the pvalue of Z when X = 116. So
X = 146
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{146 - 101}{15}[/tex]
[tex]Z = 3[/tex]
[tex]Z = 3[/tex] has a pvalue of 0.9987
X = 116
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{116 - 101}{15}[/tex]
[tex]Z = 1[/tex]
[tex]Z = 1[/tex] has a pvalue of 0.8413
0.9987 - 0.8413 = 0.1574
0.1574 = 15.74% of the player's serves are expected to be between 116 mph and 146 mph
To find the proportion of the player's serves between 116 mph and 146 mph, calculate the z-scores and use a z-table.
Explanation:To find the proportion of the player's serves between 116 mph and 146 mph, we need to calculate the z-scores for these values and then use a z-table.
The formula for calculating the z-score is z = (x - mean) / standard deviation. So, for 116 mph: z = (116 - 101) / 15 = 1; and for 146 mph: z = (146 - 101) / 15 = 3.
The z-score of 1 corresponds to a cumulative proportion of 0.8413 and the z-score of 3 corresponds to a cumulative proportion of 0.9987. So, the proportion of serves between 116 mph and 146 mph is 0.9987 - 0.8413 = 0.1574, rounded to four decimal places.
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Distance from (3,5) and (-2,-2)
Answer:5,7
Step-by-step explanation:
Complete the square for the expression
x
2
+8x
x2+8x
. Then factor the trinomial.
Answer:
x^2+8x+16
(x+4)^2
Step-by-step explanation:
x^2 +8x
Take the coefficient of the x term
8
Divide by 2
8/2 =4
Square it
4^2 =16
x^2+8x+16
We can factor it into
(x+8/2) ^2
(x+4)^2
Final answer:
Completing the square for the expression x² + 8x involves adding and subtracting 16 to form the perfect square trinomial (x + 4)² and then subtracting 16. The factored form of the resulting trinomial is (x + 4)² - 16.
Explanation:
To complete the square for the expression x² + 8x, we need to find a number that, when added to 8x, will make the expression a perfect square trinomial. The number we're looking for is ²⁄8², which is 16. So, we add and subtract 16 within the expression to maintain equality.
The expression becomes x² + 8x + 16 - 16. Now the first three terms form a perfect square trinomial (x + 4)², and we still have -16. The expression is (x + 4)² - 16.
To factor the trinomial, we write it as the square of a binomial: (x + 4)². Hence, the expression x² + 8x can be written as (x + 4)² - 16, which is the factored form of the trinomial resulting from the completion of the square.
What is the growth or decay and the percentage rate of Y=23(0.292)^x
Answer:
So the decay percentage rate is of 70.8%
Step-by-step explanation:
An exponentil function has the following format:
[tex]y = ca^{x}[/tex]
In which c is a constant.
If a>1, we have that a = 1 + r and r is the growth rate.
If a<1, we have that a = 1 - r and r is the decay rate.
In this problem:
a = 0.292
A is lesser than 1, so r is the decay rate.
1 - r = 0.292
r = 1 - 0.292
r = 0.708
So the decay percentage rate is of 70.8%
You have two jobs. One job pays nine dollars per hour and the other job pays $7.50 per hour. You worked 18 hours last week and earned $145.50. How many hours did you work at each job?
Answer:
[tex] Y =\frac{16.5}{1.5}= 11[/tex]
[tex] X = 18-11=7[/tex]
And then we conclude that for the first job he works 7 hours and for the second job 11 hours
Step-by-step explanation:
We can define the following notation:
[tex]X[/tex] represent the number of hours worked for one job
[tex]Y[/tex] represent the number of hours worked for the other job
[tex]p_x = 9[/tex] represent the hourly payment for the first job
[tex]p_y = 7.50[/tex] represent the hourly payment for the other job
And we can define the following equations:
[tex] X+ Y= 18[/tex] (1) represent the toal number of hours worked
[tex] 9X +7.5 Y = 145.50[/tex] (2) represent the total amount earned
From equation (1) if we solve for X we got:
[tex] X = 18-Y[/tex] (3)
Replacing equation (3) into equation (2) we got:
[tex] 9(18-Y) +7.5 Y =145.50[/tex]
And after solve the equation we can find the value of Y:
[tex] 162 -9Y +7.5 Y =145.50[/tex]
[tex]16.5 = 1.5 Y[/tex]
[tex] Y =\frac{16.5}{1.5}= 11[/tex]
And solving for X from equation (3) we got:
[tex] X = 18-11=7[/tex]
And then we conclude that for the first job he works 7 hours and for the second job 11 hours
8 people share 1 pizza. How much each person receive ?
Answer:
1
Step-by-step explanation:
because one pizza is cut into 8 so
1 piece would be even
=1
The amount of pizza received by each person is 0.125.
What are arithmetic operations?The arithmetic operations are the fundamentals of all mathematical operations. The example of these operators are addition, subtraction, multiplication and division.
The number of pizza is 1.
And, the total number of people is 8.
Now, the share of each people can be obtained as follows,
Consider that each people get the equal share.
The arithmetic operation used in this case is division.
Then, the problem can be solved by dividing 1 by 8 as follows,
⇒ 1 ÷ 8 = 1/8 = 0.125
The result of the division is a decimal number which shows that the amount of pizza for each people is the smallest part less than the whole.
Hence, the share of pizza received by each person is 0.125.
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ow much fencing is required to enclose a circular gardan whose radius is 14m used 22 / 7 for pi
To enclose a circular garden with a radius of 14m, you would need 88 meters of fencing.
Explanation:To find the amount of fencing required to enclose a circular garden, you need to calculate the circumference of the garden. The formula for circumference is given by C = 2πr, where r is the radius of the garden.
Given that the radius is 14m, you can use the value of π as 22/7. So, the circumference is C = 2 * (22/7) * 14 = 88m.
Therefore, you would need 88 meters of fencing to enclose the circular garden.
ILL GIVE YOU BRAINLIST !! *have to get it right ! *
Find the slope of the line represented in the table.
Answer:
2/3
Step-by-step explanation:
To find the slope take the difference of the y's over the difference of the x's
(8-6)/ (12-9)
2/3
The vertex of the graph of a quadratic function is in the second quadrant. The related equation has no real solutions. Which statement is true?
a) The graph opens up.
b) The graph opens down.
c) The y-intercept is 0.
d) The axis of symmetry is x = 0.
Answer: a) The graph opens up.
Step-by-step explanation:
The vertex is the minimum/maximum of a parabola.
We know that the vertex is in the second quadrant (so it is in the quadrant of positive y values and negative x values)
We also know that it has no real roots, so the graph never touches the x-axis, and knowing that the vertex is above the x-axis, then the graph must open upwards.
Then the correct option is:
a) The graph opens up.
When the vertex of the graph of a quadratic function is in the second quadrant and has no real solutions, this means that the graph opens down. The other statements provided are not necessarily true in this specific context.
Explanation:In the context of this problem related to quadratic functions, if the vertex of the graph is in the second quadrant and there are no real solutions, the correct statement is (b) the graph opens down. Quadratic functions in the second quadrant that have no real solutions indeed point downwards. This is due to the fact that the function cannot touch or cross the x-axis (indicating that there are no real solutions).
As for option (c), the y-intercept could be any real number, so it does not have to be 0. Concerning option (d), the axis of symmetry can't be x = 0 as the vertex is in the second quadrant and x = 0 is the y-axis. Lastly, option (a) is false because if the graph opened up it would pass through the x-axis, providing real solutions, contrary to what is given in the problem.
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Find all nth roots. Write your answers in polar form.
−√2+i√2, n=5
Answer:
help me and I will help you
Solve for v.
7(v-3)+7v = 21
Simplify your answer as much as possible.
Answer:
v = 3
Step-by-step explanation:
7(v - 3) + 7v = 21
distribute the 7 into the parentheses
7v -21 +7v = 21
combine like terms
14v - 21 = 21
add 21 on both sides
14v + 21 - 21 = 21 + 21 which equals 14v = 42
divide both sides by 14 to isolate v
14v/14 = 42/14
v = 3
hope this helps :)
survey found that 68 % of callers complain about the service they receive from a call center. State the assumptions and determine the probability of each event described below. (a) The next three consecutive callers complain about the service. (b) The next two callers complain, but not the third. (c) Two out of the next three calls produce a complaint. (d) None of the next 10 calls produces a complaint.
Answer:
(a) 0.3144
(b) 0.1497
(c) 0.654
(d) [tex]1.125\times 10^{-5}[/tex]
Step-by-step explanation:
It is given that in a survey 68% of callers complain about the service.
So the probability that a caller complaint about the service = 0.68
Therefore probability that caller does not complain for the service = 1-0.68 = 0.32
(a) Probability of next three caller complain about service [tex]=0.68\times 0.68\times 0.68=0.3144[/tex]
(b) Probability that next two caller complain but not third
[tex]=0.68\times 0.68\times 0.32=0.1497[/tex]
(c) Two out of three calls produce a complaint
[tex]=^3C_20.68^2\times 0.32=0.654[/tex]
(d) None of the 10 calls produce a complaint
[tex]=0.32^{10}=1.125\times 10^{-5}[/tex]
The probability of individual and consecutive complaints from a call center are calculated using the given percentage of complaints. These calculations are based on the assumption of a consistent 68% complaint rate and that each complaint is an independent event.
Explanation:The subject of this question is probability, a concept in mathematics. To answer your question, we need to make some assumptions. We must assume that each caller's complaint is an independent event - that is, whether one caller complains does not affect whether the next caller will complain. We also need to assume that the 68% complaint rate is consistent, meaning it does not vary with time or for any other reason.
(a) The probability of three consecutive callers complaining would be (0.68)^3 = 0.314432.
(b) The probability of the next two callers complaining, but not the third would be (0.68)^2* (1-0.68) = 0.147456.
(c) Two out of the next three calls producing a complaint could occur in three ways (CCN, CNC, NCC where C is a complaining caller and N is a non-complainer). So, it would be 3*(0.68)^2* (1-0.68) = 0.442368.
(d) The probability of none of the next 10 calls producing a complaint would be (1 - 0.68)^10 = 0.0000040859.
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Find x, y, z, and w.
[x 6 (2x-1) y 9 9y] = [(2x-3) z 5 7 (w+1) (8y+7)]
Answer:
(x, y, z, w) = (3, 7, 6, 8)
Step-by-step explanation:
Your list equation seems to resolve to 6 equations:
x = 2x -36 = z2x -1 = 5y = 79 = w +19y = 8y +7The first equation tells you ...
0 = x -3 . . . . . subtract x
3 = x . . . . . . . add 3
We can check this in the third equation:
2(3) -1 = 5 . . . true
The fifth equation tells you ...
8 = w . . . . . . . subtract 1
We can check the value of y in the last equation:
9(7) = 8(7) +7 . . . true
The variable values are ...
(x, y, z, w) = (3, 7, 6, 8)
Using the equation y=x-5, describe how to create a
system of linear equations with an infinite number of
solutions.
Answer:
You would create another equations that have same form as given equation.
For example, given y = (2/3)x - 5
=> Other one could be y = 2[(1/3)x - 5/2]
...
Hope this helps!
:)
Answer:
Sample Response/Explanation: To have an infinite number of solutions, the equations must graph the same line. That means the equations must be equivalent. To form an equivalent equation, use the properties of equality to rewrite the given equation in a different form. Add, subtract, multiply, or divide both sides of the equation by the same amount.
Step-by-step explanation:
PLEASE HELP ME I WILL MARK BRAINLIEST!!!
Answer:
v= 205.3
Step-by-step explanation:
The formula to solve a pyramid is v=(l*h*w)/3.
11*7*8=616
616/3=205.333.... (repeating 3)
about 205.3
~sorry I couldn't draw it out~
It takes 15 hours for 4 men to paint a room.
How many men would be needed to paint the room in 10 hours?
Answer:
6
Step-by-step explanation:
If there was one man, he would have taken 15×4= 60 hours
To complete the job in 10 hours, 60÷10 = 6 men will be needed
To paint the room in 10 hours instead of 15, the calculation shows that 6 men would be needed. This is determined through the concept of work rate and inverse proportions, calculating the total man-hours and then dividing by the desired hours.
The question involves determining the number of men needed to paint a room in 10 hours, given it takes 15 hours for 4 men to paint the same room. This problem can be solved using the concept of work rate and inverse proportions, which is a common method in Mathematics to deal with time and work problems. First, we calculate the work rate of the 4 men together and then find how many men would be needed to complete the job in 10 hours at a proportional rate.
Calculation steps:
Identify the original work rate: 4 men take 15 hours.Compute the total man-hours required for the job: 4 men × 15 hours = 60 man-hours.To find the time it would take for an unknown number of men to complete the same task in 10 hours, set up the equation: x men × 10 hours = 60 man-hours.Solving for x gives x = 60 man-hours / 10 hours = 6 men.Therefore, 6 men would be needed to paint the room in 10 hours.
30 points!!!!!!! EASY MATH!!!!!!!!!! PLZ HELP!!!!
f(x)=(x+1)^2
What is the domain of f?
Answer:
Domain: all real values
Step-by-step explanation:
f(x)=(x+1)^2
The domain is the values for x
We can use any value for x in the equation
Domain: all real values
Answer:
All real values of x
Step-by-step explanation:
f(x) = (x + 1)² is defined for all x
Hence the domain includes all real values of x
The table shows data representing the total surface area
of a square pyramid with a slant height of 5 centimeters.
Answer:
B and C
Step-by-step explanation:
Answer:
parabola and quadratic
Step-by-step explanation:
just answered it
Reading 183 pages in 61 minutes is a pace of how many pages a minute
Answer: 3 pages per minute
Step-by-step explanation:
61x=183
x= the amount of pages
183/61= 3 pages
You can check this by multiplying 3 by 61 which = 183.
Answer:
3
Step-by-step explanation:
183 x
----- = -----
61 1
Cross Multiply
183= 61x
Divide
3=x
When a number is decreased by 17% the result is 15 what is the original number to the nearest tenth
Answer:
The original number was 18.1.
Step-by-step explanation:
This question can be solved using a simple rule of three.
When a number is decreased by 17% the result is 15.
So 15 is 100-17 = 83%. The original number is 100%. Then
15 - 0.83
x - 1
[tex]0.83x = 15[/tex]
[tex]x = \frac{15}{0.83}[/tex]
[tex]x = 18.1[/tex]
The original number was 18.1.
17 24 26 13 what's the mean
Answer:
20
Step-by-step explanation:
Mean is the average of the numbers. You get the average by adding all the numbers and then dividing by the amount of numbers there are.
Example: 17+24+26+13=80 divided by 4 is 20
In one school, a half of all students who like math like science as well. Also, in that school, a third of all students who like science also like math.
b
In that school, what is the ratio of the number of students who like math to the number of students who like science?
Answer: 2/3
Step-by-step explanation:
N is the total number of students
M is the number of students thta like math
S is the number of students that like science.
We know that half of the elements in M also are elements from S
And a third of the elements of S also are elements of M
And because those elements are common elements for both sets, we should have that:
M/2 = S/3
then we have that:
M = (2/3)*S
The ratio is 2/3
this means that the number of students that like math is 2/3 times the number of students that like science.
The ratio of the number of students who like math to the number of students who like science is 2/3
What is ratio of two quantities?Suppose that we've got two quantities with measurements as 'a' and 'b'
Then, their ratio(ratio of a to b) a:b
or
[tex]\dfrac{a}{b}[/tex]
We usually cancel out the common factors from both the numerator and the denominator of the fraction we obtained. Numerator is the upper quantity in the fraction and denominator is the lower quantity in the fraction).
Suppose that we've got a = 6, and b= 4, then:
[tex]a:b = 6:2 = \dfrac{6}{2} = \dfrac{2 \times 3}{2 \times 1} = \dfrac{3}{1} = 3\\or\\a : b = 3 : 1 = 3/1 = 3[/tex]
Remember that the ratio should always be taken of quantities with same unit of measurement. Also, ratio is a unitless(no units) quantity.
For the given case, we can assume the real quantities by variables.
Let we have:
M = Number of students who like mathsS = Number of students who like science.By given information, we have:
M/2 students like science too.S/3 students like maths too.Since the statement "M/2 students like science too" and "S/3 students like maths too" are same thing, so they're taking about same students who like math and science both, thus:
[tex]\dfrac{M}{2} = \dfrac{S}{3}\\\\\text{Multiplying both the sides by 2/S}\\\\\dfrac{M}{S} = \dfrac{2}{3}[/tex]
Thus, the ratio needed (ratio of number of students liking math to the number of students liking science) is M/N = 2/3
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2 x + 5 = 10
what is x =?
Answer:
x=[tex]\frac{5}{2}[/tex]
Step-by-step explanation:
First, subtract 5 on both sides since when you subtract 5 from 5, it will give you 0.
Basically we are trying to get rid of the +5.
2x+5-5=10-5
2x=5
Divide by 2 to get rid of the 2 that is combined with the x.
2x/2=5/2
x=[tex]\frac{5}{2}[/tex]
Answer:x=5/2
Step-by-step explanation:
2x+5=10
Subtract 5 from both sides
2x+5-5=10-5
2x=5
Divide both sides by 2
2x/2=5/2
x=5/2
Help anyone can somebody explain the answer please
Answer:
D
Step-by-step explanation:
8^2+x^2=16^2
Senior management of a consulting services firm is concerned about a growing decline in the firm’s weekly number of billable hours. The firm expects each professional employee to spend at least 40 hours per week on work. In an effort to understand this problem better, management would like to estimate the standard deviation of the number of hours their employees spend on work-related activities in a typical week. Rather than reviewing the records of all the firm’s full-time employees, the management randomly selected a sample of size 50 from the available frame. The sample mean and sample standard deviations were 46.4 and 7.2 hours, respectively. Construct a 97% confidence interval for the standard deviation of the number of hours this firm’s employees spend on work-related activities in a typical week
With 97% confidence, we estimate that the true standard deviation of the firm's employees' work hours lies within the range of approximately 5.832 to 7.950 hours per week.
To construct a 97% confidence interval for the standard deviation [tex](\(\sigma\))[/tex], we use the chi-square distribution. The formula for the confidence interval is given by:
[tex]\[ \left( \sqrt{\frac{(n-1)s^2}{\chi_{\alpha/2}^2}}, \sqrt{\frac{(n-1)s^2}{\chi_{1-\alpha/2}^2}} \right) \][/tex]
where [tex]\(n\)[/tex] is the sample size, [tex]\(s\)[/tex] is the sample standard deviation, [tex]\(\alpha\)[/tex]is the significance level, and [tex]\(\chi_{\alpha/2}^2\)[/tex] and [tex]\(\chi_{1-\alpha/2}^2\)[/tex] are the chi-square critical values.
Given that [tex]\(n = 50\)[/tex] , [tex]\(s = 7.2\)[/tex] , and [tex]\(\alpha = 0.03\)[/tex] (97% confidence level corresponds to [tex]\(\alpha/2 = 0.015\))[/tex] , we look up the critical values from the chi-square distribution table. For 49 degrees of freedom (50-1), the critical values are approximately 31.449 and 71.420.
Substitute these values into the formula:
[tex]\[ \left( \sqrt{\frac{49 \times 7.2^2}{31.449}}, \sqrt{\frac{49 \times 7.2^2}{71.420}} \right) \][/tex]
The formula for the confidence interval is:
[tex]\[ \left( \sqrt{\frac{(n-1)s^2}{\chi_{\alpha/2}^2}}, \sqrt{\frac{(n-1)s^2}{\chi_{1-\alpha/2}^2}} \right) \][/tex]
Given:
[tex]\[ n = 50, \ s = 7.2, \ \alpha = 0.03 \][/tex]
For 49 degrees of freedom (50-1), the chi-square critical values are approximately 31.449 [tex](\(\chi_{\alpha/2}^2\))[/tex] and 71.420 [tex](\(\chi_{1-\alpha/2}^2\))[/tex] .
Now, substitute these values into the formula:
[tex]\[ \left( \sqrt{\frac{49 \times 7.2^2}{31.449}}, \sqrt{\frac{49 \times 7.2^2}{71.420}} \right) \][/tex]
Calculating this yields approximately (5.832, 7.950).
Therefore, the 97% confidence interval for the standard deviation of the weekly work hours is approximately (5.832, 7.950).
In summary, with 97% confidence, we estimate that the true standard deviation of the firm's employees' work hours lies within the range of approximately 5.832 to 7.950 hours per week.
What is one tenth of 75
Answer:
the answer is 7.5. hope this helps
Answer:
7.5
Step-by-step explanation:
An inventor has developed a new, energy-efficient lawn mower engine. He claims that the engine will run continuously for 5 hours (300 minutes) on a single gallon of regular gasoline. Suppose a simple random sample of 45 engines is tested. The engines run for an average of 290 minutes, assume the population standard deviation is 20 minutes. Test the null hypothesis that the mean run time is at least 300 minutes. Use a left sided test. Use a 0.025 level of significance.
a) Find the critical value for this test.
b) Find the test statistic
c) Find the p-value for this test.
d) My conclusion is :
e) Is the test statistically significant?
f) Could I use a symmetric confidence interval to solve this problem and if so what is it?
Answer:
b,c
Step-by-step explanation:
The National Assessment of Educational Progress (NAEP) gives a math assessment every year to 12th graders in the U.S. On the math test, a score above 275 indicates that a student has the skills to balance a checkbook. For a random sample of 500 young men, the mean NAEP math score is 272 with a standard deviation of 78. Do we have evidence to support the claim that young men nationwide have a mean score below 275? The null and alternative hypotheses are H 0: μ = 275, H a: μ < 275. The level of significance is 5%. The t-test statistic is −0.86 with a P-value of 0.20. What is the correct conclusion? Group of answer choices The evidence suggests that young men nationwide have a mean score less than 275. We do not have enough evidence to conclude that the mean score is less than 275 for young men nationwide. The evidence suggests that young men nationwide have a mean score equal to 275. It is likely that these 500 young men have a mean score less than 275.
We do not have enough evidence to conclude that the mean score is less than 275 for young men nationwide.
Explanation:The null hypothesis (H0) is that the mean NAEP math score for young men nationwide is 275. The alternative hypothesis (Ha) is that the mean score is less than 275. The level of significance is 5%.
The t-test statistic is -0.86 and the p-value is 0.20. Since the p-value is greater than the significance level (0.20 > 0.05), we fail to reject the null hypothesis. This means we do not have enough evidence to conclude that the mean score is less than 275 for young men nationwide.
Learn more about Hypothesis testing here:https://brainly.com/question/34171008
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