Question 1

The number of customers that enter a store during one day is an example of:

Accepted Answer

A) a continuous random variable 
B) a discrete random variable 
C) either a continuous or a discrete random variable, depending on the number of the customers 
D) either a continuous or a discrete random variable, depending on the gender of the customers 
E) none of the above 
A) a continuous random variable 
B) a discrete random variable 
C) either a continuous or a discrete random variable, depending on the number of the customers 
D) either a continuous or a discrete random variable, depending on the gender of the customers 
E) none of the above

Question 2

For a standard normal distribution, determine that probability that z is greater than or equal to 2.67; that is, find P(z > 2.6).

Accepted Answer

A) .0478 
B) .0160 
C) .0038 
D) .1406 
E) .1331 
A) .0478 
B) .0160 
C) .0038 
D) .1406 
E) .1331

Question 3

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

Accepted Answer

A) True 
 B)False

Question 4

For a standard normal distribution, determine that probability that z is between 2.2 and 2.55; that is, find P(2.2 < z < 2.55).

Accepted Answer

A) .0085 
B) .0583 
C) .0116 
D) .0012 
E) .0487 
A) .0085 
B) .0583 
C) .0116 
D) .0012 
E) .0487

Question 5

The average fee per student (an amount that includes activities fees, technology fees, curriculum fees, etc.) at four-year colleges is $1043.The fee are normally distributed with a standard deviation of $68.To ensure no more than a 1% chance of being short, a student should budget how much for fees.

Accepted Answer

A) $1182.27 
B) $1201.44 
C) $1078.34 
D) $1437.85 
E) $1343.76 
A) $1182.27 
B) $1201.44 
C) $1078.34 
D) $1437.85 
E) $1343.76

Question 6

Suppose that we know that births at Northwest Hospital occur at an average rate of 1.6 births per hour.Assume all the Poisson conditions are met.What is the probability that one hour or more will pass between successive births at the hospital?

Accepted Answer

A) 0.20% 
B) 4.95% 
C) 20.2% 
D) 49.5% 
E) 54.5% 
A) 0.20% 
B) 4.95% 
C) 20.2% 
D) 49.5% 
E) 54.5%

Question 7

A continuous random variable may assume only fractional values in an interval or collection of intervals.

Accepted Answer

A) True 
 B)False

Question 8

Lionel receives an average of 3.0 text messages per minute.Assuming that all the Poisson conditions are met for the random variable "number of text message received in a minute," determine the average time between messages (in seconds).

Accepted Answer

A) 34 
B) 40 
C) 20 
D) 10 
E) 15 
A) 34 
B) 40 
C) 20 
D) 10 
E) 15

Question 9

A study reported by the Michigan State campus newspaper stated that the average time MSU students spent studying last month was is 58.3 hours, with a standard deviation of 14 hours.If the study time distribution is normal, what percentage of students spent less than 60 hours studying?

Accepted Answer

A) .6026 
B) .5948 
C) .6368 
D) .5478 
E) .5753 
A) .6026 
B) .5948 
C) .6368 
D) .5478 
E) .5753

Question 10

Random variable x has a uniform distribution defined by the probability density function below.Determine the probability that x has a value of at least 220.   1/100 for values of x between 200 and 300
F(x) =
0 everywhere else

Accepted Answer

A) .65 
B) .80 
C) .75 
D) .60 
E) .85 
A) .65 
B) .80 
C) .75 
D) .60 
E) .85

Question 11

Which of the following is a property of the normal probability distribution?

Accepted Answer

A) the form, or shape, of the normal curve is often illustrated as a bell-shaped curve 
B) two parameters, the mean and standard deviation determine the location and shape of the distribution 
C) the standard deviation determines the width of the curve; larger values result in wider, flatter curves 
D) approximately 99.7% of the values will be within three standard deviations of the distribution mean 
E) all of the above 
A) the form, or shape, of the normal curve is often illustrated as a bell-shaped curve 
B) two parameters, the mean and standard deviation determine the location and shape of the distribution 
C) the standard deviation determines the width of the curve; larger values result in wider, flatter curves 
D) approximately 99.7% of the values will be within three standard deviations of the distribution mean 
E) all of the above

Question 12

For a continuous probability distribution, the probability is represented by the area under the curve.

Accepted Answer

A) True 
 B)False

Question 13

Dallas Green Homes uses a normal curve to estimate next year's demand.The distribution has a mean of 163 units and a standard deviation of 36 units.According to this demand distribution.If demand exceeds 95 units, the company will have to expand.How likely is it that expansion will be necessary?

Accepted Answer

A) .9429 
B) .9706 
C) .9131 
D) .9878 
E) .8980 
A) .9429 
B) .9706 
C) .9131 
D) .9878 
E) .8980

Question 14

For a normal distribution, find the area between the mean and a point 1.64 standard deviations to the left of the mean.

Accepted Answer

A) .3554 
B) .4909 
C) .4881 
D) .4495 
E) .3749 
A) .3554 
B) .4909 
C) .4881 
D) .4495 
E) .3749

Question 15

Suppose that the high temperature on an August day in Death Valley varies between 98 and 118 degrees Fahrenheit and is uniformly distributed over this range of values.What is the expected value of the high temperature on an August day?

Accepted Answer

A) 33.3 degrees Fahrenheit 
B) 100 degrees Fahrenheit 
C) 108 degrees Fahrenheit 
D) 125 degrees Fahrenheit 
E) 216 degrees Fahrenheit 
A) 33.3 degrees Fahrenheit 
B) 100 degrees Fahrenheit 
C) 108 degrees Fahrenheit 
D) 125 degrees Fahrenheit 
E) 216 degrees Fahrenheit

Question 16

North Dakota Mining (NDM) describes its estimate of the amount of oil it will produce next year from its western North Dakota operations with a normal distribution.The distribution is centered on 5.2 million barrels and has a standard deviation of .7 million barrels.According to this distribution, how likely is it that NDM's production will be between 5.5 and 6.5 million barrels?

Accepted Answer

A) .3577 
B) .3997 
C) .3022 
D) .3508 
E) .4049 
A) .3577 
B) .3997 
C) .3022 
D) .3508 
E) .4049

Question 17

The probability of a continuous random variable taking on a value within some interval is the area under the graph of the probability density function.

Accepted Answer

A) True 
 B)False

Question 18

At Netflix, the time it takes for a returned DVD to be re-filed and for the next DVD to be submitted for shipping to the customer follows a bell-shaped pattern, with a mean of 194 seconds and a standard deviation of 42 seconds.What proportion of the "turnaround" times are less than 150 seconds?

Accepted Answer

A) .1823 
B) .1459 
C) .1312 
D) .0782 
E) .0536 
A) .1823 
B) .1459 
C) .1312 
D) .0782 
E) .0536

Question 19

For a normal distribution, find the area to the right of a value that is 1.96 standard deviations below the mean.

Accepted Answer

A) .9162 
B) .3554 
C) .9750 
D) .8790 
E) .8997 
A) .9162 
B) .3554 
C) .9750 
D) .8790 
E) .8997

Question 20

Random variable x has a uniform distribution defined by the probability density function below.Determine the probability that x has a value between 225 and 250.   1/100 for values of x between 200 and 300
F(x) =
0 elsewhere else

Accepted Answer

A) .325 
B) .25 
C) .50 
D) .20 
E) .225 
A) .325 
B) .25 
C) .50 
D) .20 
E) .225

The number of customers that enter a store during one day is an example of:

For a standard normal distribution, determine that probability that z is greater than or equal to 2.67; that is, find P(z > 2.6).

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

For a standard normal distribution, determine that probability that z is between 2.2 and 2.55; that is, find P(2.2 < z < 2.55).

The average fee per student (an amount that includes activities fees, technology fees, curriculum fees, etc.) at four-year colleges is $1043.The fee are normally distributed with a standard deviation of $68.To ensure no more than a 1% chance of being short, a student should budget how much for fees.

Suppose that we know that births at Northwest Hospital occur at an average rate of 1.6 births per hour.Assume all the Poisson conditions are met.What is the probability that one hour or more will pass between successive births at the hospital?

A continuous random variable may assume only fractional values in an interval or collection of intervals.

Lionel receives an average of 3.0 text messages per minute.Assuming that all the Poisson conditions are met for the random variable "number of text message received in a minute," determine the average time between messages (in seconds).

A study reported by the Michigan State campus newspaper stated that the average time MSU students spent studying last month was is 58.3 hours, with a standard deviation of 14 hours.If the study time distribution is normal, what percentage of students spent less than 60 hours studying?

Random variable x has a uniform distribution defined by the probability density function below.Determine the probability that x has a value of at least 220. 1/100 for values of x between 200 and 300 F(x) = 0 everywhere else

Which of the following is a property of the normal probability distribution?

For a continuous probability distribution, the probability is represented by the area under the curve.

Dallas Green Homes uses a normal curve to estimate next year's demand.The distribution has a mean of 163 units and a standard deviation of 36 units.According to this demand distribution.If demand exceeds 95 units, the company will have to expand.How likely is it that expansion will be necessary?

For a normal distribution, find the area between the mean and a point 1.64 standard deviations to the left of the mean.

Suppose that the high temperature on an August day in Death Valley varies between 98 and 118 degrees Fahrenheit and is uniformly distributed over this range of values.What is the expected value of the high temperature on an August day?

The probability of a continuous random variable taking on a value within some interval is the area under the graph of the probability density function.

At Netflix, the time it takes for a returned DVD to be re-filed and for the next DVD to be submitted for shipping to the customer follows a bell-shaped pattern, with a mean of 194 seconds and a standard deviation of 42 seconds.What proportion of the "turnaround" times are less than 150 seconds?

For a normal distribution, find the area to the right of a value that is 1.96 standard deviations below the mean.

Random variable x has a uniform distribution defined by the probability density function below.Determine the probability that x has a value between 225 and 250. 1/100 for values of x between 200 and 300 F(x) = 0 elsewhere else

An Introduction to Statistics

Descriptive Statistics I: Elementary Data Presentation and Description

Descriptive Statistics II: Additional Descriptive Measures and Data Displays

Probability

Discrete Probability Distributions

Statistical Inference: Estimating a Population Mean

Interval Estimates for Proportions, Mean Differences and Proportion Differences

Statistical Hypothesis Testing: Hypothesis Tests for a Population Mean

Hypothesis Tests for Proportions, Mean Differences and Proportion Differences

Basic Regression Analysis

Multiple Regression

F Tests and Analysis of Variance

Experimental Designonline Only

Chi-Square Tests

Filters

Exam 6: Continuous Probability Distributions

The number of customers that enter a store during one day is an example of:

For a standard normal distribution, determine that probability that z is greater than or equal to 2.67; that is, find P(z > 2.6).

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

For a standard normal distribution, determine that probability that z is between 2.2 and 2.55; that is, find P(2.2 < z < 2.55).

Suppose that we know that births at Northwest Hospital occur at an average rate of 1.6 births per hour.Assume all the Poisson conditions are met.What is the probability that one hour or more will pass between successive births at the hospital?

A continuous random variable may assume only fractional values in an interval or collection of intervals.

Lionel receives an average of 3.0 text messages per minute.Assuming that all the Poisson conditions are met for the random variable "number of text message received in a minute," determine the average time between messages (in seconds).

A study reported by the Michigan State campus newspaper stated that the average time MSU students spent studying last month was is 58.3 hours, with a standard deviation of 14 hours.If the study time distribution is normal, what percentage of students spent less than 60 hours studying?

Random variable x has a uniform distribution defined by the probability density function below.Determine the probability that x has a value of at least 220. 1/100 for values of x between 200 and 300 F(x) = 0 everywhere else

Which of the following is a property of the normal probability distribution?

For a continuous probability distribution, the probability is represented by the area under the curve.

Dallas Green Homes uses a normal curve to estimate next year's demand.The distribution has a mean of 163 units and a standard deviation of 36 units.According to this demand distribution.If demand exceeds 95 units, the company will have to expand.How likely is it that expansion will be necessary?

For a normal distribution, find the area between the mean and a point 1.64 standard deviations to the left of the mean.

Suppose that the high temperature on an August day in Death Valley varies between 98 and 118 degrees Fahrenheit and is uniformly distributed over this range of values.What is the expected value of the high temperature on an August day?

The probability of a continuous random variable taking on a value within some interval is the area under the graph of the probability density function.

At Netflix, the time it takes for a returned DVD to be re-filed and for the next DVD to be submitted for shipping to the customer follows a bell-shaped pattern, with a mean of 194 seconds and a standard deviation of 42 seconds.What proportion of the "turnaround" times are less than 150 seconds?

For a normal distribution, find the area to the right of a value that is 1.96 standard deviations below the mean.

Random variable x has a uniform distribution defined by the probability density function below.Determine the probability that x has a value between 225 and 250. 1/100 for values of x between 200 and 300 F(x) = 0 elsewhere else

An Introduction to Statistics

Descriptive Statistics I: Elementary Data Presentation and Description

Descriptive Statistics II: Additional Descriptive Measures and Data Displays

Probability

Discrete Probability Distributions

Statistical Inference: Estimating a Population Mean

Interval Estimates for Proportions, Mean Differences and Proportion Differences

Statistical Hypothesis Testing: Hypothesis Tests for a Population Mean

Hypothesis Tests for Proportions, Mean Differences and Proportion Differences

Basic Regression Analysis

Multiple Regression

F Tests and Analysis of Variance

Experimental Designonline Only

Chi-Square Tests

Filters