1. A test consists of 10 true/false questions. To pass the test a student must answer at least 6 questions correctly. If a student guesses on each question, what is the probability that the student will pass the test? (Round to three decimal places.)

A. 0.205

B. 0.377

C. 0.828

D. 0.172

2. A tennis player makes a successful first serve 51% of the time. If she serves 9 times, what is the probability that she gets exactly 3 successful first serves in? Assume that each serve is independent of the others.

A. 0.154

B. 0.133

C. 0.0635

D. 0.00184

3. Twenty percent of adults in a particular community have at least a bachelor's degree. Suppose x is a binomial random variable that counts the number of adults with at least a bachelor's degree in a random sample of 100 adults from the community. Which of the following probability statements indicates the probability that at least 30 adults have at least a bachelor's degree?

A. P(x30)

B. P(x30)

C. P(x>30)

D. P(x<30)

4. Mars, Inc. claims that 20% of its M&M plain candies are orange. A sample of 100 such candies is randomly selected. Find the mean and standard deviation for the number of orange candies in such groups of 100.

A. =20, =0.20

B. =0.020, =0.20

C. =0.20, =4.0

D. =20, =4.0

5. Based on a Comcast survey, there is a 0.8 probability that a randomly selected adult will watch prim-time TV live, instead of online, on DVR, etc. Assume that seven adults are randomly selected. Find the probability that fewer than three of the selected adults watch prime-time live.

A.0.00467

B. 0.000358

C. 0.00430

D. 0.0512

6. Determine whether the following value is a continuous random variable, discrete random variable, or not a random variable.

• a. The number of hits to a website in a week a discrete random variable, continuous random variable, or not a random variable?

A. It is a continuous random variable.

B. It is a discrete random variable.

C. It is not a random variable.

• b. Is the hair color of adults in the United States a discrete random variable, continuous random variable, or not a random variable?

A. It is a continuous random variable.

B. It is a discrete random variable.

C. It is not a random variable.

• c. Is the number of people in a restaurant that has a capacity of 200 a discrete random variable, continuous random variable, or not a random variable?

A. It is a continuous random variable.

B. It is a discrete random variable.

C. It is not a random variable.

• d. Is the number of textbook authors now eating a meal a discrete random variable, continuous random variable, or not a random variable?

A. It is a continuous random variable.

B. It is a discrete random variable.

C. It is not a random variable.

• e. Is the time it takes to drive from City A to City B a discrete random variable, continuous random variable, or not a random variable?

A. It is a continuous random variable.

B. It is a discrete random variable.

C. It is not a random variable.

• f. Is the height of a randomly selected person a discrete random variable, continuous random variable, or not a random variable?

A. It is a continuous random variable.

B. It is a discrete random variable.

C. It is not a random variable.

7. Twenty percent of adults in a particular have at least a bachelor's degree. Suppose x is a binomial random variable that counts the number of adults with at least a bachelor's degree in a random sample of 100 adults from the community. If you are using a calculator with the binompdf and binomcdf commands, which of the following is the most efficient way to calculate the probability that more than 60 adults have a bachelor's degree, P(x>60)?

A. P(x>60) = binomcdf (100,0,20,60)

B. P(x>60) = binompdf (100,0,20,60)

C. P(x>60) = 1 - binomcdf (100,0,20,59)

D. P(x>60) = 1 - binomcdf (100,0,20,60)

8. A survey showed that 82% of adults need correction (eyeglasses, contacts, surgery, etc.) for their eyesight. If 15 adults are randomly selected, find the probability that no more than 1 of them need correction for their eyesight. Is 1 a significantly low number of adults requiring eyesight correction?

The probability that no more than 1 of the 15 adults require eyesight correction is ______.? (Round to three decimal places as needed.)

Is 1 a significantly low number of adults requiring eyesight correction? (Note that a small probability is one that is less than 0.05.)

A. No, because the probability of the occurring is not small

B. No, because the probability of this occurring is small.

C. Yes, because the probability of this occurring is not small.

D. Yes, because the probability of this occurring is small.

9. A die is rolled nine times and the number of times that two shows on the upper face is counted. If this experiment is repeated many times, find the mean for the number of twos.

A. 7.5 twos

B. 3 twos

C. 2.25 twos

D. 1.5 twos

10. What does it mean to say that the trials in a binomial experiment are independent of each other?

A. No more than one trial can occur at a time.

B. The outcome of one trial does not affect the outcomes of the other trials.

C. The outcome of one trial does affect the outcome of the next trial.

D. Each trial will result in either success or failure.