When circuit boards used in the manufacture of compact disc players are tested, the long-run percentage of defectives is 5%. suppose that a batch of 250 boards has been received and that the condition of any particular board is independent of that of any other board.
a. what is the approximate probability that at least 10% of the boards in the batch are defective?
b. what is the approximate probability that there are exactly 10 defectives in the batch?

Answers

Answer 1
Final answer:

The probability that at least 10% of the boards are defective can be approximated using a normal distribution, while the exact probability of having 10 defectives in the batch can be calculated using the binomial formula. For large samples, normal approximation can be used for convenience.

Explanation:

To find the probability that at least 10% of the boards are defective, we can use the binomial distribution since each board's condition is independent of the other boards. The formula for binomial probability is P(X = k) = (n choose k) * pk * (1-p)(n-k), where n is the number of trials, p is the probability of success on each trial, and k is the number of successes. However, for large sample sizes and when the sample proportion is close to the population proportion, we can approximate the binomial distribution with a normal distribution.

To use the normal approximation, we calculate the mean and standard deviation with the formulas μ = n * p and σ = √(n * p * (1-p)). For the batch of 250 boards with 5% defective rate, μ = 250 * 0.05 = 12.5 and σ = √(250 * 0.05 * 0.95) ≈ 3.4641. We then convert the problem into a z-score and use standard normal distribution tables or software to find the probability that Z > (25 - 12.5)/3.4641.

To find the exact probability of having exactly 10 defectives in the batch, we use the binomial formula since the normal approximation is less accurate for exact probabilities. The calculation would be P(X = 10) = (250 choose 10) * 0.0510 * 0.95240.


Related Questions

A microwave is placed on top of two boxes. One box is 2 feet 5 inches tall the other box is 3 feet 11 inches tall and the other microwave is 3 feet 3 inches tall how tall are they combined?

Answers

Combined they are 9 feet 7 inches tall.
9 feet and 7 inches or 115 inches

Find all the local maxima, local minima, and saddle points of the function

Answers

what function can you post it please and thank you

Final answer:

To find local maxima, minima, and saddle points, find critical points using the first derivative test and then apply the second derivative test.

Explanation:

To find the local maxima, local minima, and saddle points of a function, we first need to find the critical points. These are the points where the derivative of the function is either zero or undefined. To check whether each critical point is a local maxima, local minima, or saddle point, we use the second derivative test.

The second derivative test states that if the second derivative is positive at a critical point, then the point is a local minimum. If the second derivative is negative, then the point is a local maxima. If the second derivative is zero, the test is inconclusive.

By applying the second derivative test to each critical point, we can determine whether it is a local maxima, local minima, or saddle point.

Mrs Rivera baked 112 cookies there are 28 students in her class how many cookies will each student receive

Answers

The students will each receive 4 cookies, you divide 112 from 28 and it is 4.

Final answer:

Each student will receive 4 cookies.

Explanation:

To find out how many cookies each student will receive, we need to divide the total number of cookies by the number of students. In this case, Mrs. Rivera baked 112 cookies and there are 28 students, so we can divide 112 by 28 to find the answer.

Divide 112 by 28: 112 ÷ 28 = 4Therefore, each student will receive 4 cookies.

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Find the exact value of cos pi/12 using half angle identities

Answers

[tex]\bf cos\left(\cfrac{{{ \theta}}}{2}\right)=\pm \sqrt{\cfrac{1+cos({{ \theta}})}{2}}\\\\ -------------------------------\\\\ \cfrac{\pi }{12}\cdot 2\implies \cfrac{\pi }{6}\qquad therefore\qquad \cfrac{\quad \frac{\pi }{6}\quad }{2}\implies \cfrac{\pi }{12}\qquad then \\\\\\ cos\left( \frac{\pi }{12} \right)\implies cos\left( \cfrac{\frac{\pi }{6}}{2} \right)=\pm\sqrt{\cfrac{1+cos\left( \frac{\pi }{6} \right)}{2}}[/tex]

[tex]\bf cos\left( \cfrac{\frac{\pi }{6}}{2} \right)=\pm\sqrt{\cfrac{1+\frac{\sqrt{3}}{2}}{2}}\implies cos\left( \cfrac{\frac{\pi }{6}}{2} \right)=\pm\sqrt{\cfrac{\frac{2+\sqrt{3}}{2}}{2}} \\\\\\ cos\left( \cfrac{\frac{\pi }{6}}{2} \right)=\pm\sqrt{\cfrac{2+\sqrt{3}}{4}}\implies cos\left( \cfrac{\frac{\pi }{6}}{2} \right)=\pm\cfrac{\sqrt{2+\sqrt{3}}}{\sqrt{4}} \\\\\\ cos\left( \cfrac{\frac{\pi }{6}}{2} \right)=\pm\cfrac{\sqrt{2+\sqrt{3}}}{2}[/tex]

Answer:

[tex]\cos \left(\frac{\pi }{12}\right)=\frac{\sqrt{2+\sqrt{3}}}{2}[/tex]

Step-by-step explanation:

To find the exact value of [tex]\cos \left(\frac{\pi }{12}\right)[/tex] using half angle identities you must:

Write [tex]\cos \left(\frac{\pi }{12}\right)[/tex] as [tex]\cos \left(\frac{\frac{\pi }{6}}{2}\right)[/tex]

Using the half angle identity [tex]\cos \left(\frac{x}{2}\right)=\sqrt{\frac{1+\cos \left(x\right)}{2}}[/tex]

[tex]\cos \left(\frac{\frac{\pi }{6}}{2}\right)=\sqrt{\frac{1+\cos \left(\frac{\pi }{6}\right)}{2}}[/tex]

Use the following identity: [tex]\cos \left(\frac{\pi }{6}\right)=\frac{\sqrt{3}}{2}[/tex]

[tex]\sqrt{\frac{1+\cos \left(\frac{\pi }{6}\right)}{2}}=\sqrt{\frac{1+\frac{\sqrt{3}}{2}}{2}}[/tex]

Join [tex]1+\frac{\sqrt{3}}{2}[/tex]

[tex]1+\frac{\sqrt{3}}{2}=\frac{1\cdot \:2}{2}+\frac{\sqrt{3}}{2}=\frac{2+\sqrt{3}}{2}[/tex]

[tex]\sqrt{\frac{1+\frac{\sqrt{3}}{2}}{2}}=\sqrt{\frac{\frac{2+\sqrt{3}}{2}}{2} } =\sqrt{\frac{2+\sqrt{3}}{4}} =\frac{\sqrt{2+\sqrt{3}}}{\sqrt{4}}=\frac{\sqrt{2+\sqrt{3}}}{2}[/tex]

Therefore,

[tex]\cos \left(\frac{\pi }{12}\right)=\frac{\sqrt{2+\sqrt{3}}}{2}[/tex]

simplify the complex fraction. 9/y/6/y-7

Answers

[tex]\bf \cfrac{\quad \frac{9}{y}\quad }{\frac{6}{y-7}}\implies \cfrac{9}{y}\cdot \cfrac{y-7}{6}\implies \cfrac{9}{6}\cdot \cfrac{y-7}{y}\implies \cfrac{3}{2}\cdot \cfrac{y-7}{y}\implies \cfrac{3y-21}{2y}[/tex]

Solve the system of linear equations. separate the x- and y- values with a coma. 20x=-58-2y
17x=-49-2y

Answers

The best way to solve is by using elimination method.
20x = -58 - 2y
17x = -49 - 2y
Multiply second equation by -1
20x = -58 - 2y
-17x = 49 + 2y
Add equations.
3x = -9 
Divide.
x = -3
Plug in -3 into one of the equations.
17(-3) = -49 - 2y
-51 = -49 - 2y
Add 49 to both sides.
-2 = -2y
Divide.
1 = y
So your solution is (-3, 1).
I hope this helps love! :)

Find the probability that the mean annual preciptiation will be between 32 and 34 inches. variable is normally distributed

Answers

Supposing, for the sake of illustration, that the mean is 31.2 and the std. dev. is 1.9.

This probability can be calculated by finding z-scores and their corresponding areas under the std. normal curve.  
                                                                     34 in - 31.2 in
The area under this curve to the left of z = -------------------- = 1.47 (for 34 in)
                                                                           1.9
                                                                      32 in - 31.2 in
and that to the left of 32 in   is               z = ---------------------- = 0.421
                                                                             1.9

Know how to use a table of z-scores to find these two areas?  If not, let me know and I'll go over that with you.


My TI-83 calculator provided the following result:

normalcdf(32, 34, 31.2, 1.9) = 0.267  (answer to this sample problem)

Anjali went to Citizens Bank and borrowed $7,000 at a rate of 8%. The date of the loan was September 20. Anjali hoped to repay the loan on January 20. Assuming the loan is based on ordinary interest, Anjali will pay back how much interest on January 20?      A. $187.18 B. $187.17 C. $189.78 D. $188.22

Answers

From September 20 to January 20, there are 4 months only which is equivalent to 1/3 of a year. The interest earned by the investment, P, made is calculated 
               I = P x i x n
where I is the interest, P is the principal amount, i is the interest rate, and n is the number of years. Substituting the known values,
                I = ($7000)(0.08)(1/3)
                I = $186.67
Hence, the answer to this item is $186.67. 

Answer:

$189.78

Step-by-step explanation:

"The computation of the interest on January 20 is shown below:

= Principal × interest rate × number of days ÷ total number of days in a year

= $7,000 × 8% × 122 days ÷ 360 days

= $7,000 × 8% × 0.338

= $189.78

The 122 days are calculated below:

September - 10 days

October - 31 days

November - 30 days

December - 31 days

January  - 20 days

Total    - 122 days

And we assume the 360 days in a year"

what is x in _-18x−45=-12_

Answers

Hello there~

-18x - 45 = -12

Let's start by adding 45 to both sides

-18x - 45 + 45 = -12 + 45

-18x = 33

Then divide both sides by -18

-18x/-18 = 33/-18

x = -11/6

I hope this helps!

Sam is a waiter at a local restaurant where he earns wages of $7 per hour. Sam figures that he also earns about $5 in tips for each person he serves. Sam works 6 hours on a particular day.

Answers

are you just looking for the equation... 6*7+5x or 42+5x

Answer:

y=5x+42

Where y is the money he earns and x is the number of person he serves.

Step-by-step explanation:

Let the number of person he serves =x

It is given that he earns $5 as tip for each person he serves.

Hence total tip earned for serving x person=5x

His fixed wages are $7 per hour and he works for 6 hours a day. Hence his wages per day are $7*6 =$42

Hence total money earned for a day , say y can be represented as

y=5x+42

Two trains leave the station at the same time, one heading east and the other west. The eastbound train travels 20 miles per hour faster than the westbound train. If the two trains are 750 miles apart after 5 hours, what is the rate of the eastbound train?

Answers

east bound train = x

westbound train = x-20 ( 20 miles slower than east bound)

5x + 5(x-20) = 750

5x +5x -100=750

10x -100 = 750

10x =850

x = 850/10 = 85

east bound train is 85 mph

west bound train is 85-20 = 65 mph


check: 85*5 = 425

65*5 = 325

325+425 = 750

Fractions EXPLAIN your answer.

Answers

Answer and explanation included in the photo

You earn $20 per hour doing landscaping work your total earnings depend on the amount of hours you spend landscaping what is the independent variable

Answers

The amount earned per hour
The number of hours would be the independent (x-value), while the total amount you earn is the dependent variable.

given the rectangle below, which of the following transformations will map the figure onto itself?

Answers

The answer is the option B. rotate 90 degrees counterclokwise and then rotate 270 degrees counterclockwise.

See that two consecutive rotations counterclockwise are equivalent to one single roration counterclockwise as long as the angles sum up the same.

Given that 90° + 270 ° = 360° means that the two rotaions are equivalent to one 360° rotation, and so the final figure will be the same as the original figure.

one quart or one gram is greater

Answers

One quart is way bigger than one gram
One quart is bigger that the one gram

rob cuts a 15-foot wire into 8 equal pieces.about how long is each piece ?

Answers

15/8 = 1.875 ft per piece....so each piece is just short of 2 ft
Divide 15 by 8 to get 1.875. Each piece is 1.875 feet long.

Please give me brainliest answer.

A food truck sells salads for $6.50 each and drinks for $2.00 each. The food truck’s revenue from selling a total of 209 salads and drinks in one day was $836.50. How many salads were sold that day? A) 77 B) 93 C) 99 D) 105

Answers

Create an equation to figure out how much salad was sold that day. S is for the number of salads. D is for the number of drinks.

$6.5s + $2d = $836.5
s + d = 209
s = 209 - d

Plug in the values. 

6.5 (209 - d) + 2d = 836.5

1358.5 - 6.5d + 2d = 836.5
-4.5d = -522
d = 116

s = 209 - 116
= 93

Answer: Letter B 

Hope that helps! ★ If you have further questions about this question or need more help, feel free to comment below or post another question and send the link to me. -UnicornFudge aka Nadia 
its d I think I'm not sure I'm in class so I can't help that well

Find the limit, if it exists. (if an answer does not exist, enter dne.) lim (x, y) → (0, 0) x4 − 20y2 x2 + 10y2

Answers

Traveling along the x-axis, we have

[tex]\displaystyle\lim_{(x,y)\to(0,0)}\frac{x^4-20y^2}{x^2+10y^2}=\lim_{x\to0}\frac{x^4}{x^2}=\lim_{x\to0}x^2=0[/tex]

On the other hand, along the y-axis we get

[tex]\displaystyle\lim_{(x,y)\to(0,0)}\frac{x^4-20y^2}{x^2+10y^2}=\lim_{y\to0}\frac{-20y^2}{10y^2}=\lim_{y\to0}(-2)=-2[/tex]

Therefore the limit doesn't exist.
Final answer:

The limit of the expression as (x, y) approaches (0, 0) does not exist.

Explanation:

To find the limit as (x, y) approaches (0, 0) of the expression \(\frac{x^4 - 20y^2}{x^2 + 10y^2}\), we can try approaching the limit along different paths. Let's consider approaching along the x-axis (y=0) and along the y-axis (x=0) separately.

Approaching along the x-axis: \(\lim_{{(x, 0) \to (0, 0)}} \frac{{x^4 - 20(0)^2}}{{x^2 + 10(0)^2}} = \lim_{{(x, 0) \to (0, 0)}} \frac{{x^4}}{{x^2}} = \lim_{{(x, 0) \to (0, 0)}} x^2 = 0.

Approaching along the y-axis: \(\lim_{{(0, y) \to (0, 0)}} \frac{{(0)^4 - 20y^2}}{{(0)^2 + 10y^2}} = \lim_{{(0, y) \to (0, 0)}} \frac{{-20y^2}}{{10y^2}} = \lim_{{(0, y) \to (0, 0)}} -2 = -2.

Since the limit approaches different values along different paths, the limit does not exist.

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which of the following represents the factorization of the trinomal below

Answers

B is the correct answer. If you use the distributive property correctly you will see why.

(4x+3)(2x+1)= 8x^2+4x+6x+3
= 8x^2+10x+3


please vote my answer brainliest. thanks!

What is the common ratio for the geometric sequence? 54,36,24,16... Enter your answer in the box.

Answers

The common ratio of the geometric sequence is: 2/3.

Common Ratio of a Geometric Sequence

Common ratio, r = a term divided by the consecutive term in the series.

Given the geometric sequence, 54,36,24,16...

common ratio (r) = 16/24 = 2/3.

24/36 = 2/3.

36/54 = 2/3.

Therefore, the common ratio of the geometric sequence is: 2/3.

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Don James wants to invest $55,000 to earn $6260 per year. he can invest in B-rates bonds paying 14% per year or in a certificate of Deposit (CD) paying 8% per year. How much money should be invested in each to realize exactly $6260 in interest per year?

Answers

don james payed for (CD) paying $6,337

If p(a) = 0.25 and p(b) = 0.65, assuming independence of events, then p(a and
b.is:

Answers

0.25x0.65=0.1625
full answer

The Independent events is 0.1625.Events A and B are considered independent if the likelihood of each event's occurrence is unaffected by the occurrence of the other.

Find the independent events?

P(A/B) is equal to P(A.B)/P(B) by definition (A). P(A) = P(B) / P(B) (as A, B are Independent events).

Events A and B are considered independent if the likelihood of each event's occurrence is unaffected by the occurrence of the other. P(A) = P(AB) = 1/2, which suggests that the likelihood of event A occurring has not changed as a result of the occurrence of event B.

P(0.25) = P(0.25 * 0.65) = 1/2

P(0.25) = 0.1625.

The Independent events is 0.1625 .

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justin sold 300 liter of soda at a baseball game.how much is this in milliliters?

Answers

If Justin sold 300 liters of soda, then he would have sold 300000 milliliters of soda. 1 liter= 1000 milliliters

Answer:

300,000 mililiters

Step-by-step explanation:

Remember that in international system the convertions are really easy because they are done 10 by 10, so from liters to mili, there are 3 spots, 1000, so there are 1000 mili-liters in a liter, so you just need to multiply the 300 liters of soda by 1000, which is 300,000 mililiters and that is what Justin sold at the baseball game in mililiters.

Suppose f−1 is the inverse of a differentiable function f and f(4) = 0, f′(4) = 1. find (f−1)′(0).

Answers

Give me a heart and I'll tell you the answer

Elspeth knows that PI r=9.42cm. What would she need to do to find the circumference?

Answers

Take that pi = 3.142

pi r = 9.42
r = 9.42/3.142 = 2.998
d = 2 x 2.998 = 5.996
Cricumference = 3.142 x 5.996 = 18.839 cm

You need to get the radius then multiply by 2 to get the diameter then you can get the circumference.

The answer would be A! :)

A random variable x takes four possible values, 0, 2, a, and b, where a and b are unknown numbers. if pr[x = 0] = 0.2, pr[x=2] = 0.4, pr[x = a] = 0.3, e[x] = 2.8 and it is the case that a + b = 6, what is the missing value of a ?
a.-1.0
b.5.0
c.7.0
d.cannot be determined without more information
e.none of the above

Answers

Final answer:

The missing value of the random variable X can be determined by solving the equation e[x] = 2.8 and substituting the known values. By solving the equation, we find that the missing value is c. 7.

Explanation:

a. In words, X = A random variable that takes four possible values: 0, 2, a, and b.

b. X~ A missing value that represent an unknown number for the random variable X.

c. In words, X = The missing value of the random variable X, denoted by a.

d. X A missing value that we need to determine.

In this case, the missing value of a can be found by substituting the known values into the equation a + b = 6. Since b = 6 - a, we can substitute this expression into the equation e[x] = 2.8 and solve for a. From the equation, we get 0.2(0) + 0.4(2) + 0.3(a) + 0.3(6 - a) = 2.8.

Solving this equation gives us a = 7. Therefore, the missing value of a is 7, so the correct answer is c.

What is the next letter a,z,e,b,I,y,o

Answers

The next letter in the sequence should be "C". This is because the odd numbered letters are vowels "A,E,I,O" and the even numbered letters are the are a letter from the end of the alphabet and then  number from the beginning e.g. "Z,B,Y" therefore the next letter in the sequence would have to be "C". If this question helped please make it Brainliest. Thanks.

Three boys share 28 toy cars equally. How many cars did each boy get and how many were left over

Answers

Divide 28 by 3 and count how many are left over.

28 / 3 = 9 1/3

So each boy had 9 toy cars, and because you can't have 1/3 cars, you round 1/3 to 1. So there was 1 left over car.
9 cars with 1 car left over

A professor has recorded exam grades for 20 students in his class, but one of the grades is no longer readable. If the mean score on the exam was 81 and the mean of the 19 readable scores is 85, what is the value of the unreadable score?

Answers

20 students....mean score of exam was 81...

x / 20 = 81
x = 81 * 20
x = 1620....this is the total of all the grades added up

(1620 - x) / 19 = 85
1620 - x = 85 * 19
1620 - x = 1615
-x = 1615 - 1620
-x = - 5
x = 5 <=== weird answer...but thats what I am getting

The value of the unreadable score is [tex]5[/tex]

It should be noted that the mean of numbers simply means the average of the numbers.

Since the mean score of the 20 students was 81, then the total score will be: [tex]= 20 * 81= 1620[/tex]

Then, since the mean score of the 19 students was 85, their total scores will be: = [tex]19 * 85 = 1615[/tex]

The value of the unreadable score will be:

[tex]= 1620 - 1615 = 5[/tex].

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A random sample of is selected from this population. find the probability that the sample mean is greater than 2.1 but less than 2.5.

Answers

its 2.2 less than 2.5 and greater than 2.1
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