1. The time it takes me to wash the dishes is uniformly distributed between 11 minutes and 17 minutes.

What is the probability that washing dishes tonight will take me between 13 and 15 minutes?

Give your answer accurate to two decimal places.

2. For a standard normal distribution, find:

P(z < -2.68)

Express the probability as a decimal rounded to 4 decimal places.

3.For a standard normal distribution, find:

P(z > 0.58)

Express the probability as a decimal rounded to 4 decimal places.

4.For a standard normal distribution, find:

P(1.2 < z < 1.95)

5.For a standard normal distribution, find:

P(z < c) = 0.8921

Find c rounded to two decimal places.

6.For a standard normal distribution, find:

P(z > c) = 0.3726

Find c rounded to two decimal places.

7.The combined SAT scores for the students at a local high school are normally distributed with a mean of 1487 and a standard deviation of 298. The local college includes a minimum score of 1785 in its admission requirements.

What percentage of students from this school earn scores that fail to satisfy the admission requirement?

P(X< 1785) =

Enter your answer as a percent accurate to 1 decimal place (do not enter the "%" sign). Answers obtained using exactz-scores orz-scores rounded to 3 decimal places are accepted.

8.The physical plant at the main campus of a large state university recieves daily requests to replace florecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 64 and a standard deviation of 9. Using the empirical rule (as presented in the book), what is the approximate percentage of lightbulb replacement requests numbering between 64 and 91?

Do not enter the percent symbol.

ans =

9.Assume that 12 jurors are randomly selected from a population in which 74% of the people are Mexican-Americans. Refer to the probability distribution table below and find the indicated probabilities.xxP(x)P(x)

0 0+

1 0+

2 0.0001

3 0.0005

4 0.0031

5 0.0141

6 0.0469

7 0.1143

8 0.2034

9 0.2573

10 0.2197

11 0.1137

12 0.027

10.Find the probability of exactly 6 Mexican-Americans among 12 jurors.

P(x=6)=P(x=6)=

11.Find the probability of 6 or fewer Mexican-Americans among 12 jurors.

P(x6)=P(x6)=

12.If a seed is planted, it has a 90% chance of growing into a healthy plant.

If 11 seeds are planted, what is the probability that exactly 4 don't grow?

A poll is given, showing 20% are in favor of a new building project.

13.If 3 people are chosen at random, what is the probability that exactly 2 of them favor the new building project?

14.A manufacturing machine has a 9% defect rate.

If 8 items are chosen at random, what is the probability that at least one will have a defect?

15.About 7% of the population has a particular genetic mutation. 900 people are randomly selected.

Find the mean for the number of people with the genetic mutation in such groups of 900.

16.About 10% of the population has a particular genetic mutation. 100 people are randomly selected.

Find the standard deviation for the number of people with the genetic mutation in such groups of 100.

17.When taking a 16 question multiple choice test, where each question has 3 possible answers, it would be unusual to get or more questions correct by guessing alone. Note: Of course it would be unusual to get 16 questions correct. You need to enter the smallest possible number of questions to make getting "that many correct" unusual.

Give your answer in the box above as a whole number.

18.Multiple-choice questions each have 5 possible answers, one of which is correct. Assume that you guess the answers to 4 such questions.

Use the multiplication rule to find the probability that the first three guesses are wrong and the fourth is correct. That is, find P(WWWC)P(WWWC), where C denotes a correct answer and W denotes a wrong answer.

(round answer to 4 decimal places)

P(WWWC)=P(WWWC)=

What is the probability of getting exactly one correct answer when 4 guesses are made?

(round answer to 4 decimal places)

P(exactly one correct answer) =1.

19.You have a really annoying stapler that seems to randomly jam. On any given attempt to staple, it seems to independently jam 18.9% of the time.

a) Out of 300 papers stapled, what is the probability that your stapler will jam 46 times or fewer?

b) Find the mean and standard deviation for the number of jammed staples out of 300 attempts.

Mean: Standard Deviation:

c) Does the normal approximation apply? Explain.

d) Use the normal distribution (withoutcontinuity correction) to find the probability that your stapler will jam 46 times or fewer out of 300 attempts.

e) Use the normal distribution (withcontinuity correction) to find the probability that your stapler will jam 46 times or fewer out of 300 attempts.

20.A study was conducted to determine whether there were significant differences between medical students admitted through special programs (such as retention incentive and guaranteed placement programs) and medical students admitted through the regular admissions criteria. It was found that the graduation rate was 92% for the medical students admitted through special programs. Be sure to enter at least 4 digits of accuracy for this problem!

If 11 of the students from the special programs are randomly selected, find the probability that at least 10 of them graduated.

prob = At least 4 digits!

If 11 of the students from the special programs are randomly selected, find the probability thateactly8 of them graduated.

prob = At least 4 digits!

If 11 of the students from the special programs are randomly selected, find the probability thatat most8 of them graduated.

prob = At least 4 digits!

21.Assume that the proportion of voters who prefer Candidate A is p=0.614p=0.614. Organization D conducts a poll of n=5n=5 voters.

LetXrepresent the number of voters polled who prefer Candidate A. Use some form of appropriate technology (e.g., your calculator or statistics software like Excel, R, or StatDisk) to find thecumulativeprobability distribution.

(Report answers accurate to 4 decimal places.)

kP(X<k)

0

1

2

3

4

5

22.Assume that a procedure yields a binomial distribution with a trial repeated n=5n=5 times. Use some form of technology to find the probability distribution given the probability p=0.153p=0.153 of success on a single trial.

(Report answers accurate to 4 decimal places.)

kP(X=k)

0

1

2

3

4

5