Multiple Choice .Pick the correct choice.

1.Delores must grade a driver's test completed by a group of training students. She knows that driver's test scores are normally distributed with = 50 and= 6. Students are required to score in the top 75% of students on the test in order to pass the test and continue on with the training course. Which score do students need to obtain at a minimum in order to pass the test and continue with the course?

a.X= 40

b.X= 54

c.X= 60

d.X= 46

2.What is the probability of randomly selecting az-score less thanz= -1.55 from a normal distribution?

a.p= 0.0606

b.p= 0.4394

c.p= 0.3433

d.p= 0.9394

3.Which statement accurately describes the proportions in the body of a normal distribution?

a.Body proportions are always .50.

b.Body proportions are always .50.

c.Body proportions on the right side of thez-score are less than 0.50; on the left side, they are greater than 0.50.

d.Body proportions on the right side of thez-score are greater than 0.50; on the left side, they are less than 0.50.

4.Which of the following is a requirement for a random sample?

a.Every individual has an equal chance of being selected.

b.There must be sampling with replacement.

c.The probabilities cannot change during a series of selections.

d.Each of the other 3 choices are correct.

5.Mitchell is getting ready to take a baseball rules exam in order to become certified as a baseball umpire in his local community. Past scores on the rules exam form a normal distribution with= 80 and= 6. Mitchell must score in the highest 25% of the distribution in order to become a certified umpire. Which minimum score does Mitchell need to obtain on the rules exam to become a certified umpire?

a.X= 86

b.X= 76

c.X= 84

d.X= 81

6.A normal distribution has a mean of= 60 with= 8. For this population, which is theXvalue that corresponds to the third quartile?

a.X= 54.64

b.X= 62.45

c.X= 67.14

d.X= 65.36

7.Which proportion of a normal distribution is located in the tail abovez= +1.50?

a.0.9332

b.0.0668

c.0.4501

d.0.4332

8.A sample ofn= 49 scores withM= 43 is selected from a population with= 40 with= 21. What is the standard error for the sample mean?

a._M= 6

b._M= 3

c._M= 2

d._M= 8

9.A vertical line is drawn through a normal distribution atz= -1.20. Which proportion of the distribution is on the right-hand side of the line?

a.0.7698

b.0.3849

c.0.8849

d.0.1151

10.A sample obtained from a population with= 48 has a standard error of_M= 6. How many scores are in the sample?

a.n= 36

b.n= 8

c.n= 64

d.n= 12

11.A population is normally distributed with a mean of = 145 and= 20. Which is the percentile rank forX= 136?

a.17.36%

b.35.64%

c.32.64%

d.67.36%