Question 1

For a continuous random variable x, the probability density function f(x)  represents the

Accepted Answer

A)   probability at a given value of x.
B)   area under the curve at x.
C)   area under the curve to the right of x.
D)   height of the function at x.

Question 2

Joe's Record World has two stores and sales at each store follow a normal distribution.For store 1, μ = $2,000 and σ = $200 per day; for store 2, μ = $1,900 and σ = $300 per day.Which store is more likely to have a day's sales in excess of $2200?

Accepted Answer

A)   Store 1
B)   Store 2
C)   Store 1 and store 2 are equally likely
D)   More information is needed

Question 3

Whenever the probability is proportional to the length of the interval in which the random variable can assume a value, the random variable is _____ distributed.

Accepted Answer

A)   uniformly
B)   normally
C)   Poisson
D)   exponentially

Question 4

Given that z is a standard normal random variable, what is the probability that -2.08  z  1.46?

Accepted Answer

A)   0.9091
B)   0.4812
C)   0.4279
D)   0.0533

Question 5

z is a standard normal random variable.The P(-1.96  z  1.4)  equals

Accepted Answer

A)   0.9442.
B)   0.0558.
C)   0.8942.
D)   0.1058.

Question 6

The assembly time for a product is uniformly distributed between 2 to 10 minutes.What is the value of probability density function in the interval between 2 and 10?

Accepted Answer

A)   0.25
B)   0.125
C)   8.00
D)   0.00

Question 7

A continuous random variable may assume

Accepted Answer

A)   all values in an interval or collection of intervals.
B)   only integer values in an interval or collection of intervals.
C)   only fractional values in an interval or collection of intervals.
D)   all the positive integer values in an interval.

Question 8

The z score for the standard normal distribution

Accepted Answer

A)   is always equal to zero.
B)   can never be negative.
C)   can be either negative or positive.
D)   is always equal to the mean.

Question 9

Which of the following probability distributions have the same value for mean, median, and mode​?

Accepted Answer

A)   Uniform
B)   Normal
C)   ​Exponential
D)   ​Poisson

Question 10

The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes.The probability that her trip will take longer than 80 minutes is

Accepted Answer

A)   1.00.
B)   0.40.
C)   0.20.
D)   0.80.

Question 11

x is a normally distributed random variable with a mean of 7 and a standard deviation of 2.The probability that x is between 6.48 and 7.56 is

Accepted Answer

A)   0.9524.
B)   0.0476.
C)   0.7872.
D)   0.2128.

Question 12

Given that z is a standard normal random variable, what is the probability that -2.51  z  -1.53?

Accepted Answer

A)   0.4950
B)   0.4370
C)   0.0570
D)   0.9310

Question 13

A normal distribution with a mean of 0 and a standard deviation of 1 is called

Accepted Answer

A)   a probability density function.
B)   uniform probability distribution.
C)   a standard normal distribution.
D)   exponential probability distribution.

Question 14

Which of the following is not a characteristic of the normal probability distribution?

Accepted Answer

A)   The mean, median, and the mode are equal
B)   The mean of the distribution can be negative, zero, or positive
C)   The distribution is symmetrical
D)   The standard deviation must be 1

Question 15

Which of the following are continuous random variables?​ I. The weight of an elephant
II) The time to answer a questionnaire
III) The number of floors in a skyscraper
IV) The square feet of countertop in a kitchen

Accepted Answer

A)   ​I and II only
B)   ​III and IV only
C)   ​I, II and IV only​
D)   ​I, II, II, and IV

Question 16

Consider a binomial probability experiment with n = 3 and p = 0.1.Then, the probability of x = 0 is

Accepted Answer

A)   0.
B)   0.0001.
C)   0.001.
D)   0.729.

Question 17

A normal probability distribution

Accepted Answer

A)   is a continuous probability distribution.
B)   is a discrete probability distribution.
C)   can be either continuous or discrete.
D)   must have a standard deviation of 1.

Question 18

For the standard normal probability distribution, the area to the right of the mean is

Accepted Answer

A)   1.
B)   3.09.
C)   1.96.
D)   0.5.

Question 19

The assembly time for a product is uniformly distributed between 2 to 10 minutes.The probability of assembling the product in less than 6 minutes is

Accepted Answer

A)   0.
B)   0.50.
C)   0.25.
D)   1.

Question 20

The probability that a continuous random variable takes any specific value

Accepted Answer

A)   is equal to zero.
B)   is at least 0.5.
C)   depends on the probability density function.
D)   is very close to 1.0.

Exam 6: Continuous Probability Distributions

A normal distribution with a mean of 0 and a standard deviation of 1 is called

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Given that z is a standard normal random variable, what is the probability that -2.08 z 1.46?

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For the standard normal probability distribution, the area to the right of the mean is

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Which of the following is not a characteristic of the normal probability distribution?

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The z score for the standard normal distribution

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A continuous random variable may assume

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The probability that a continuous random variable takes any specific value

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The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes.The probability that her trip will take longer than 80 minutes is

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z is a standard normal random variable.The P(-1.96 z 1.4) equals

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x is a normally distributed random variable with a mean of 7 and a standard deviation of 2.The probability that x is between 6.48 and 7.56 is

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For a continuous random variable x, the probability density function f(x) represents the

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Whenever the probability is proportional to the length of the interval in which the random variable can assume a value, the random variable is _____ distributed.

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Consider a binomial probability experiment with n = 3 and p = 0.1.Then, the probability of x = 0 is

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Which of the following probability distributions have the same value for mean, median, and mode​?

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Given that z is a standard normal random variable, what is the probability that -2.51 z -1.53?

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Joe's Record World has two stores and sales at each store follow a normal distribution.For store 1, μ = $2,000 and σ = $200 per day; for store 2, μ = $1,900 and σ = $300 per day.Which store is more likely to have a day's sales in excess of $2200?

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Which of the following are continuous random variables?​ I. The weight of an elephant II) The time to answer a questionnaire III) The number of floors in a skyscraper IV) The square feet of countertop in a kitchen

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A normal probability distribution

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The assembly time for a product is uniformly distributed between 2 to 10 minutes.The probability of assembling the product in less than 6 minutes is

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The assembly time for a product is uniformly distributed between 2 to 10 minutes.What is the value of probability density function in the interval between 2 and 10?

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Which of the following probability distributions have the same value for mean, median, and mode?

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Which of the following are continuous random variables? I. The weight of an elephant II) The time to answer a questionnaire III) The number of floors in a skyscraper IV) The square feet of countertop in a kitchen

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