Question 1

A property of continuous distributions is that

Accepted Answer

A)  as with discrete random variables, the probability distribution can be approximated by a smooth curve. 
B)  probabilities for continuous variables can be approximated using discrete random variables. 
C)  unlike discrete random variables, probabilities can be found using tables. 
D)  unlike discrete random variables, the probability that a continuous random variable equals a specific value is zero [P(X = x) = 0]. 
A)  as with discrete random variables, the probability distribution can be approximated by a smooth curve. 
B)  probabilities for continuous variables can be approximated using discrete random variables. 
C)  unlike discrete random variables, probabilities can be found using tables. 
D)  unlike discrete random variables, the probability that a continuous random variable equals a specific value is zero [P(X = x) = 0].

Question 2

At an oceanside nuclear power plant, seawater is used as part of the cooling system. This raises the temperature of the water that is discharged back into the ocean. The amount that the water temperature is raised has a uniform distribution over the interval from 10° to 25° C. What is the probability that the temperature increase will be less than 20° C?

Accepted Answer

A)  .40 
B)  .67 
C)  .80 
D)  1.00 
A)  .40 
B)  .67 
C)  .80 
D)  1.00

Question 3

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time is no more than 3 minutes?

Accepted Answer

A)  .3012 
B)  .6988 
C)  .4346 
D)  .5654 
E)  .0821 
A)  .3012 
B)  .6988 
C)  .4346 
D)  .5654 
E)  .0821

Question 4

At an oceanside nuclear power plant, seawater is used as part of the cooling system. This raises the temperature of the water that is discharged back into the ocean. The amount that the water temperature is raised has a uniform distribution over the interval from 10° to 25° C. What is the standard deviation of the temperature increase?

Accepted Answer

A)  10.12 
B)  4.33 
C)  7.50 
D)  1.25 
A)  10.12 
B)  4.33 
C)  7.50 
D)  1.25

Question 5

An apple juice producer buys all his apples from a conglomerate of apple growers in one northwestern state. The amount of juice obtained from each of these apples is approximately normally distributed with a mean of 2.25 ounces and a standard deviation of .15 ounce. 77 percent of the apples will contain at least how many ounces of juice?

Accepted Answer

A)  2.12 
B)  2.38 
C)  2.36 
D)  2.14 
A)  2.12 
B)  2.38 
C)  2.36 
D)  2.14

Question 6

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m. What is the probability that a randomly selected depth is within 1 standard deviation of the mean?

Accepted Answer

A)  .320 
B)  .576 
C)  .600 
D)  1.000 
A)  .320 
B)  .576 
C)  .600 
D)  1.000

Question 7

The mean and median are the same for a normal distribution.

Accepted Answer

A) True 
 B)False

Question 8

A normal distribution with mean equal to zero and a standard deviation equal to one is called the ________ normal distribution.

Accepted Answer

A)  continuous 
B)  uniform 
C)  exponential 
D)  standard 
A)  continuous 
B)  uniform 
C)  exponential 
D)  standard

Question 9

The weight of a product is normally distributed with a standard deviation of .5 ounces. What should the average weight be if the production manager wants no more than 10 percent of the products to weigh more than 4.8 ounces?

Accepted Answer

A)  3.52 
B)  3.64 
C)  5.44 
D)  4.16 
A)  3.52 
B)  3.64 
C)  5.44 
D)  4.16

Question 10

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random from the population is between 29.75 and 30.5 inches long?

Accepted Answer

A)  .4332 
B)  .4878 
C)  .0546 
D)  .9210 
A)  .4332 
B)  .4878 
C)  .0546 
D)  .9210

Question 11

The normal probability distribution is a discrete probability distribution.

Accepted Answer

A) True 
 B)False

Question 12

In a statistical study, the random variable X = 1 if the house is colonial, and X = 0 if the house is not colonial. The random variable X is continuous.

Accepted Answer

A) True 
 B)False

Question 13

Given that the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?

Accepted Answer

A)  .9972 
B)  .5000 
C)  .9544 
D)  .4772 
A)  .9972 
B)  .5000 
C)  .9544 
D)  .4772

Question 14

An apple juice producer buys all his apples from a conglomerate of apple growers in one northwestern state. The amount of juice obtained from each of these apples is approximately normally distributed with a mean of 2.25 ounces and a standard deviation of .15 ounce. What is the probability that a randomly selected apple will contain between 2.00 and 2.50 ounces?

Accepted Answer

A)  .500 
B)  .9044 
C)  .9525 
D)  .9544 
A)  .500 
B)  .9044 
C)  .9525 
D)  .9544

Question 15

The binomial random variable x consists of n = 60 trials and has the probability of failure q = .4. Using the normal approximation, compute the probability of 32 successes.

Accepted Answer

.0618
µ = np = (60)(.6) = 36
σ

Question 16

The binomial random variable x consists of n = 60 trials and has the probability of failure q = .4. Using the normal approximation, compute the probability of 45 successes.

Accepted Answer

.0063
µ = np = (60)(

Question 17

If the random variable of x is normally distributed, ________ percent of all possible observed values of x will be within two standard deviations of the mean.

Accepted Answer

A)  99.73 
B)  68.26 
C)  95.00 
D)  95.44 
A)  99.73 
B)  68.26 
C)  95.00 
D)  95.44

Question 18

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time exceeds 3 minutes?

Accepted Answer

A)  .3012 
B)  .6988 
C)  .4346 
D)  .5654 
E)  .0821 
A)  .3012 
B)  .6988 
C)  .4346 
D)  .5654 
E)  .0821

Question 19

Values of the standard normal random variable are measured

Accepted Answer

A)  with reference to specific units. 
B)  in the units in which the mean is measured. 
C)  in the number of standard deviations from the mean. 
D)  in squared units in which the mean is measured. 
E)  None of these answers are correct. 
A)  with reference to specific units. 
B)  in the units in which the mean is measured. 
C)  in the number of standard deviations from the mean. 
D)  in squared units in which the mean is measured. 
E)  None of these answers are correct.

Question 20

The relationship between the standard normal random variable, z, and normal random variable, X, is that

Accepted Answer

A)  only the normal random variable X is continuous. 
B)  only the standard normal variable z is continuous. 
C)  the standard normal variable z counts the number of standard deviations that the value of the normal random variable X is away from its mean. 
D)  the values of the standard normal random variable z cannot be negative. 
E)  the values of the normal random variable X cannot be negative. 
A)  only the normal random variable X is continuous. 
B)  only the standard normal variable z is continuous. 
C)  the standard normal variable z counts the number of standard deviations that the value of the normal random variable X is away from its mean. 
D)  the values of the standard normal random variable z cannot be negative. 
E)  the values of the normal random variable X cannot be negative.

A property of continuous distributions is that

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time is no more than 3 minutes?

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m. What is the probability that a randomly selected depth is within 1 standard deviation of the mean?

The mean and median are the same for a normal distribution.

A normal distribution with mean equal to zero and a standard deviation equal to one is called the ________ normal distribution.

The weight of a product is normally distributed with a standard deviation of .5 ounces. What should the average weight be if the production manager wants no more than 10 percent of the products to weigh more than 4.8 ounces?

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random from the population is between 29.75 and 30.5 inches long?

The normal probability distribution is a discrete probability distribution.

In a statistical study, the random variable X = 1 if the house is colonial, and X = 0 if the house is not colonial. The random variable X is continuous.

Given that the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?

The binomial random variable x consists of n = 60 trials and has the probability of failure q = .4. Using the normal approximation, compute the probability of 32 successes.

The binomial random variable x consists of n = 60 trials and has the probability of failure q = .4. Using the normal approximation, compute the probability of 45 successes.

If the random variable of x is normally distributed, ________ percent of all possible observed values of x will be within two standard deviations of the mean.

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time exceeds 3 minutes?

Values of the standard normal random variable are measured

The relationship between the standard normal random variable, z, and normal random variable, X, is that

An Introduction to Business Statistics and Analytics

Descriptive Statistics and Analytics: Tabular and Graphical Methods

Descriptive Statistics and Analytics: Numerical Methods

Probability and Probability Models

Predictive Analytics I: Trees, K-Nearest Neighbors, Naive Bayes,

Discrete Random Variables

Sampling Distributions

Confidence Intervals

Hypothesis Testing

Statistical Inferences Based on Two Samples

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression and Model Building

Predictive Analytics Ii: Logistic Regression, Discriminate Analysis,

Time Series Forecasting and Index Numbers

Nonparametric Methods

Decision Theory

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Exam 7: Continuous Random Variables

A property of continuous distributions is that

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time is no more than 3 minutes?

While conducting experiments, a marine biologist selects water depths from a uniformly distributed collection that vary between 2.00 m and 7.00 m. What is the probability that a randomly selected depth is within 1 standard deviation of the mean?

The mean and median are the same for a normal distribution.

A normal distribution with mean equal to zero and a standard deviation equal to one is called the ________ normal distribution.

The weight of a product is normally distributed with a standard deviation of .5 ounces. What should the average weight be if the production manager wants no more than 10 percent of the products to weigh more than 4.8 ounces?

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of .2 inches. What is the probability that a sheet selected at random from the population is between 29.75 and 30.5 inches long?

The normal probability distribution is a discrete probability distribution.

In a statistical study, the random variable X = 1 if the house is colonial, and X = 0 if the house is not colonial. The random variable X is continuous.

Given that the length an athlete throws a hammer is a normal random variable with mean 50 feet and standard deviation 5 feet, what is the probability he throws it between 50 feet and 60 feet?

The binomial random variable x consists of n = 60 trials and has the probability of failure q = .4. Using the normal approximation, compute the probability of 32 successes.

The binomial random variable x consists of n = 60 trials and has the probability of failure q = .4. Using the normal approximation, compute the probability of 45 successes.

If the random variable of x is normally distributed, ________ percent of all possible observed values of x will be within two standard deviations of the mean.

The cashier service time at the local branch of the Rivertown bank has an exponential distribution with a mean of 2.5 minutes. What is the probability that the service time exceeds 3 minutes?

Values of the standard normal random variable are measured

The relationship between the standard normal random variable, z, and normal random variable, X, is that

An Introduction to Business Statistics and Analytics

Descriptive Statistics and Analytics: Tabular and Graphical Methods

Descriptive Statistics and Analytics: Numerical Methods

Probability and Probability Models

Predictive Analytics I: Trees, K-Nearest Neighbors, Naive Bayes,

Discrete Random Variables

Sampling Distributions

Confidence Intervals

Hypothesis Testing

Statistical Inferences Based on Two Samples

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression and Model Building

Predictive Analytics Ii: Logistic Regression, Discriminate Analysis,

Time Series Forecasting and Index Numbers

Nonparametric Methods

Decision Theory

Filters