Think about a density curve that consists of two line segments. The first goes from the point (0, 1) to the point (0.1, 1). The second goes from (0.1, 1) to (0.7, 2) in the xy-plane. What percent of observations fall below 0.10?

a) 0.05

b) 1.00

c) 0.45

d) 0.10

e) 0.90

f) None of the above

Question 2

Think about a density curve that consists of two line segments. The first goes from the point (0, 1) to the point (0.4, 1). The second goes from (0.4, 1) to (0.8, 2) in the xy-plane. What percent of observations fall between 0.4 and 0.8?

a) 0.50

b) 0.05

c) 0.60

d) 0.40

e) 1.00

f) None of the above

Question 3

Consider a uniform density curve defined from x = 0 to x = 5. What percent of observations fall below 4?

a) 0.20

b) 0.80

c) 0.92

d) 0.40

e) 0.25

f) None of the above

Question 4

Consider a uniform density curve defined from x = 0 to x = 9. What percent of observations fall between 1 and 6?

a) 0.17

b) 0.68

c) 0.56

d) 0.67

e) 0.11

f) None of the above

Question 5

Consider a spinner that, after a spin, will point to a number between zero and 1 with uniform probability. Determine the probability: P(¹₆ X ¹₂).

a) 0.50

b) 0.67

c) 0.17

d) 1.00

e) 0.33

f) None of the above

Question 6

The heights of students in a class are normally distributed with mean 57 inches and standard deviation 7 inches. Use the Empirical Rule to determine the interval that contains the middle 68% of the heights.

a) [50, 64]

b) [43, 71]

c) [43, 78]

d) [46, 68]

e) [36, 78]

f) None of the above

Question 7

The length of time needed to complete a certain test is normally distributed with mean 83 minutes and standard deviation 10 minutes. Find the probability that it will take less than 95 minutes to complete the test.

a) 0.8849

b) 0.5000

c) 0.5575

d) 0.1151

e) 0.4425

f) None of the above

Question 8

If X is normally distributed with a mean of 20 and a standard deviation of 2, find P(20 X 22.6).

a) 0.903

b) 0.503

c) 0.703

d) 0.403

e) 0.603

f) None of the above

Question 9

Suppose that X is normally distributed with a mean of 60 and a standard deviation of 3. What is P(X 64.05)?

a) 0.089

b) 0.092

c) 0.091

d) 0.411

e) 0.911

f) None of the above

Question 10

Suppose that x is normally distributed with a mean of 50 and a standard deviation of 10. What is P(x 69.50)?

a) 0.474

b) 0.974

c) 0.478

d) 0.026

e) 0.975

f) None of the above

Question 11

Suppose that x is normally distributed with a mean of 50 and a standard deviation of 9. What is P(33.53 x 70.97)?

a) 0.495

b) 0.466

c) 0.490

d) 0.956

e) 0.471

f) None of the above

Question 12

At a college the scores on the chemistry final exam are approximately normally distributed, with a mean of 73 and a standard deviation of 14. The scores on the calculus final are also approximately normally distributed, with a mean of 80 and a standard deviation of 14. A student scored 79 on the chemistry final and 82 on the calculus final. Relative to the students in each respective class, in which subject did the student do better?

a) The student did equally well in each course

b) Calculus

c) There is no basis for comparison

d) Chemistry

e) None of the above

Question 13

Find a value of c so that P(Z c) = 0.53.

a) -0.08

b) 0.58

c) 0.92

d) 1.08

e) 0.08

f) None of the above