# The total area underneath any normal curve is equal to

# Multiple Choice

19. If x is uniformly distributed over the interval 8 to 12, inclusively (8 x 12), then the probability, P(9 x 11), is __________________.

a) 0.250

b) 0.500

c) 0.333

d) 0.750

e) 1.000

2Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

20. If x is uniformly distributed over the interval 8 to 12, inclusively (8 x 12), then the probability, P(10.0 x 11.5), is __________________.

a) 0.250

b) 0.333

c) 0.375

d) 0.500

e) 0.750

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

21. If x is uniformly distributed over the interval 8 to 12, inclusively (8 x 12), then the probability, P(13 x 15), is __________________.

a) 0.250

b) 0.500

c) 0.375

d) 0.000

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

22. If x is uniformly distributed over the interval 8 to 12, inclusively (8 x 12), then P(x < 7) is __________________.

a) 0.500

b) 0.000

c) 0.375

d) 0.250

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

23. If x is uniformly distributed over the interval 8 to 12, inclusively (8 x 12), then P(x 11) is __________________.

a) 0.750

b) 0.000

c) 0.333

d) 0.500

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

24. If x is uniformly distributed over the interval 8 to 12, inclusively (8 x 12), then P(x 10) is __________________.

a) 0.750

b) 0.000

c) 0.333

d) 0.500

e) 0.900

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

25. If a continuous random variable x is uniformly distributed over the interval 8 to 12, inclusively, then P(x = exactly 10) is __________________.

a) 0.750

b) 0.000

c) 0.333

d) 0.500

e) 0.900

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Hard

26. If x, the time (in minutes) to complete an oil change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the height of this distribution, f(x), is __________________.

a) 1/10

b) 1/20

c) 1/30

d) 12/50

e) 1/60

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Easy

27. If x, the time (in minutes) to complete an oil change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the mean of this distribution is __________________.

a) 50

b) 25

c) 10

d) 15

e) 5

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

28. If x, the time (in minutes) to complete an oil change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the standard deviation of this distribution is __________________.

a) unknown

b) 8.33

c) 0.833

d) 2.89

e) 1.89

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

29. If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the probability that an oil change job is completed in 25 to 28 minutes, inclusively, i.e., P(25 x 28) is __________________.

a) 0.250

b) 0.500

c) 0.300

d) 0.750

e) 81.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

30. If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the probability that an oil change job is completed in 21.75 to 24.75 minutes, inclusively, i.e., P(21.75 x 24.25) is __________________.

a) 0.250

b) 0.333

c) 0.375

d) 0.000

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

31. If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the probability that an oil change job is completed in 33 to 35 minutes, inclusively, i.e., P(33 x 35) is __________________.

a) 0.5080

b) 0.000

c) 0.375

d) 0.200

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

32. If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the probability that an oil change job is completed in less than 17 minutes, i.e., P(x < 17) is __________________.

a) 0.500

b) 0.300

c) 0.000

d) 0.250

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

33. If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the probability that an oil change job is completed in less than or equal to 22 minutes, i.e., P(x 22) is __________________.

a) 0.200

b) 0.300

c) 0.000

d) 0.250

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

34. If x, the time (in minutes) to complete an change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 x 30), then the probability that an oil change job will be completed 24 minutes or more, i.e., P(x 24) is __________________.

a) 0.100

b) 0.000

c) 0.333

d) 0.600

e) 1.000

Ans:

Response: See section 6.1, The Uniform Distribution

Difficulty: Medium

35. The normal distribution is an example of _______.

a) a discrete distribution

b) a continuous distribution

c) a bimodal distribution

d) an exponential distribution

e) a binomial distribution

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Easy

36. The total area underneath any normal curve is equal to _______.

a) the mean

b) one

c) the variance

d) the coefficient of variation

e) the standard deviation

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Easy

37. The area to the left of the mean in any normal distribution is equal to _______.

a) the mean

b) 1

c) the variance

d) 0.5

e) -0.5

Ans:

Response: See section 6.2, Normal Distribution

Difficulty: Easy