Question 1

The ________ distribution would most likely be used to describe the distribution of time between arrivals of customers at the grocery store.

Accepted Answer

A)  normal 
B)  exponential 
C)  Poisson 
D)  binomial 
E)  uniform 
A)  normal 
B)  exponential 
C)  Poisson 
D)  binomial 
E)  uniform

Question 2

The standard deviation of a standard normal distribution is always equal to 1.

Accepted Answer

A) True 
 B)False

Question 3

The mean life of a pair of shoes is 40 months with a standard deviation of 8 months. If the life of the shoes is normally distributed, how many pairs of shoes out of one million will need replacement before 36 months?

Accepted Answer

A)  500,073 
B)  808,573 
C)  191,537 
D)  308,537 
A)  500,073 
B)  808,573 
C)  191,537 
D)  308,537

Question 4

The z value tells us the number of standard deviations that a value, x, is from the mean.

Accepted Answer

A) True 
 B)False

Question 5

An aptitude test has a mean score of 80 and a standard deviation of 5. The population of scores is normally distributed. What raw score corresponds to the 70th percentile?

Accepted Answer

A)  77.4 
B)  83.5 
C)  82.6 
D)  76.5 
A)  77.4 
B)  83.5 
C)  82.6 
D)  76.5

Question 6

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 19 successes.

Accepted Answer

Approximately 0.
µ = np = (60)

Question 7

The actual weight of hamburger patties is an example of a continuous random variable.

Accepted Answer

A) True 
 B)False

Question 8

The standard deviation of a standard normal distribution is always equal to ________.

Accepted Answer

A)  1 
B)  .5 
C)  0 
D)  −1 
A)  1 
B)  .5 
C)  0 
D)  −1

Question 9

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 no less than 55 feet?

Accepted Answer

A)  .8413 
B)  .1587 
C)  .6826 
D)  .3174 
A)  .8413 
B)  .1587 
C)  .6826 
D)  .3174

Question 10

The random variable x has a uniform distribution when x lies between the values of 4 and 10. When x = 10, what is the value of f(x)?

Accepted Answer

A)  0 
B)  1 
C)  1/6 
D)  1/14 
A)  0 
B)  1 
C)  1/6 
D)  1/14

Question 11

The area under the normal curve between z = 0 and z = 1 is ________ the area under the normal curve between z = 1 and z = 2.

Accepted Answer

A)  less than 
B)  greater than 
C)  equal to 
D)  less than, greater than, or equal to, depending on the value of the mean, 
E)  less than, greater than, or equal to, depending on the value of the standard deviation, 
A)  less than 
B)  greater than 
C)  equal to 
D)  less than, greater than, or equal to, depending on the value of the mean, 
E)  less than, greater than, or equal to, depending on the value of the standard deviation,

Question 12

Suppose that the times required for a cable company to fix cable problems in the homes of its customers are uniformly distributed between 40 minutes and 65 minutes. What is the probability that a randomly selected cable repair visit falls within 2 standard deviations of the mean?

Accepted Answer

A)  .75 
B)  1.00 
C)  .58 
D)  .86 
A)  .75 
B)  1.00 
C)  .58 
D)  .86

Question 13

A local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below.
   Compute the standardized quantile value Oi for i = 4.

Accepted Answer

−.5 O₄ = (z value for

Question 14

The number of defective pencils in a total lot of 1000 is an example of a continuous random variable.

Accepted Answer

A) True 
 B)False

Question 15

All continuous random variables are normally distributed.

Accepted Answer

A) True 
 B)False

Question 16

The first step to constructing a normal probability plot is to

Accepted Answer

A)  calculate Oi. 
B)  compute area i/(n + 1). 
C)  construct a box-and-whiskers plot. 
D)  order the values in the data. 
A)  calculate Oi. 
B)  compute area i/(n + 1). 
C)  construct a box-and-whiskers plot. 
D)  order the values in the data.

Question 17

If the mileage per gallon for a car is normally distributed, 32 mpg has a z score of 1.2, and 24 mpg has a z score of −.4, what is the mean mpg of the distribution?

Accepted Answer

A)  28 
B)  26 
C)  30 
D)  38 
A)  28 
B)  26 
C)  30 
D)  38

Question 18

The local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below.
   Compute the standardized quantile value Oi for i = 11.

Accepted Answer

1.02 O₁₁ = (z value fo

Question 19

Find z when the area between z and −z is .9030.

Accepted Answer

A)  1.50 
B)  1.30 
C)  .12 
D)  1.66 
A)  1.50 
B)  1.30 
C)  .12 
D)  1.66

Question 20

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. Only 5 percent of the students taking the test scored higher than what grade?

Accepted Answer

A)  70.04 
B)  67.96 
C)  55.48 
D)  83.81 
A)  70.04 
B)  67.96 
C)  55.48 
D)  83.81

The ________ distribution would most likely be used to describe the distribution of time between arrivals of customers at the grocery store.

The standard deviation of a standard normal distribution is always equal to 1.

The mean life of a pair of shoes is 40 months with a standard deviation of 8 months. If the life of the shoes is normally distributed, how many pairs of shoes out of one million will need replacement before 36 months?

The z value tells us the number of standard deviations that a value, x, is from the mean.

An aptitude test has a mean score of 80 and a standard deviation of 5. The population of scores is normally distributed. What raw score corresponds to the 70th percentile?

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 19 successes.

The actual weight of hamburger patties is an example of a continuous random variable.

The standard deviation of a standard normal distribution is always equal to ________.

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 no less than 55 feet?

The random variable x has a uniform distribution when x lies between the values of 4 and 10. When x = 10, what is the value of f(x)?

The area under the normal curve between z = 0 and z = 1 is ________ the area under the normal curve between z = 1 and z = 2.

Suppose that the times required for a cable company to fix cable problems in the homes of its customers are uniformly distributed between 40 minutes and 65 minutes. What is the probability that a randomly selected cable repair visit falls within 2 standard deviations of the mean?

A local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Compute the standardized quantile value O_i for i = 4.

The number of defective pencils in a total lot of 1000 is an example of a continuous random variable.

All continuous random variables are normally distributed.

The first step to constructing a normal probability plot is to

If the mileage per gallon for a car is normally distributed, 32 mpg has a z score of 1.2, and 24 mpg has a z score of −.4, what is the mean mpg of the distribution?

The local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Compute the standardized quantile value O_i for i = 11.

Find z when the area between z and −z is .9030.

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. Only 5 percent of the students taking the test scored higher than what grade?

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

Exam 7: Continuous Random Variables

The ________ distribution would most likely be used to describe the distribution of time between arrivals of customers at the grocery store.

The standard deviation of a standard normal distribution is always equal to 1.

The mean life of a pair of shoes is 40 months with a standard deviation of 8 months. If the life of the shoes is normally distributed, how many pairs of shoes out of one million will need replacement before 36 months?

The z value tells us the number of standard deviations that a value, x, is from the mean.

An aptitude test has a mean score of 80 and a standard deviation of 5. The population of scores is normally distributed. What raw score corresponds to the 70th percentile?

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 19 successes.

The actual weight of hamburger patties is an example of a continuous random variable.

The standard deviation of a standard normal distribution is always equal to ________.

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 no less than 55 feet?

The random variable x has a uniform distribution when x lies between the values of 4 and 10. When x = 10, what is the value of f(x)?

The area under the normal curve between z = 0 and z = 1 is ________ the area under the normal curve between z = 1 and z = 2.

Suppose that the times required for a cable company to fix cable problems in the homes of its customers are uniformly distributed between 40 minutes and 65 minutes. What is the probability that a randomly selected cable repair visit falls within 2 standard deviations of the mean?

A local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Compute the standardized quantile value Oi for i = 4.

The number of defective pencils in a total lot of 1000 is an example of a continuous random variable.

All continuous random variables are normally distributed.

The first step to constructing a normal probability plot is to

If the mileage per gallon for a car is normally distributed, 32 mpg has a z score of 1.2, and 24 mpg has a z score of −.4, what is the mean mpg of the distribution?

The local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Compute the standardized quantile value Oi for i = 11.

Find z when the area between z and −z is .9030.

A set of final examination grades in a calculus course was found to be normally distributed with a mean of 69 and a standard deviation of 9. Only 5 percent of the students taking the test scored higher than what grade?

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

A local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Compute the standardized quantile value O_i for i = 4.

The local airport in a midwestern state keeps track of the percentage of flights arriving within 15 minutes of their scheduled arrivals. The stem-and-leaf plot of the data for one year is below. Compute the standardized quantile value O_i for i = 11.