Question 1

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 the above 
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 the above

Question 2

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20.What percentage of the time will the number of boxes received weekly be greater than 200

Accepted Answer

A) 100% 
B) 25% 
C) 0% 
D) 50% 
A) 100% 
B) 25% 
C) 0% 
D) 50%

Question 3

At an ocean-side 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 25ºC. Suppose that a temperature increase of more than 18ºC is considered to be potentially dangerous to the environment.What is the probability that at any point of time,the temperature increase is potentially dangerous?

Accepted Answer

A) 0.47 
B) 0.72 
C) 0.28 
D) 0.50 
A) 0.47 
B) 0.72 
C) 0.28 
D) 0.50

Question 4

During the past six months,73.2% of US households purchased sugar.Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.99% of the households spent less than what amount?

Accepted Answer

A) $5.66 
B) $10.78 
C) $6.81 
D) $9.63 
A) $5.66 
B) $10.78 
C) $6.81 
D) $9.63

Question 5

For a normal population with a mean of 10 and a variance 4,the P(X $\ge$ 10)is ___.

Accepted Answer

A) 1.0 
B) 0.5 
C) 0.75 
D) 0.25 
A) 1.0 
B) 0.5 
C) 0.75 
D) 0.25

Question 6

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 7

A continuous probability distribution having a rectangular shape where the probability is evenly distributed over an interval of numbers is called a uniform probability distribution.

Accepted Answer

A) True 
 B)False

Question 8

The price-to-earning ratio for firms in a given industry is distributed according to normal distribution.In this industry,a firm with a standard normal variable value of Z = 1:

Accepted Answer

A) Has an above average price-to-earning ratio. 
B) Has a below average price-to-earnings ratio. 
C) Has an average price-to-earnings ratio. 
D) May have an above average or below average price-to-earnings ratio. 
A) Has an above average price-to-earning ratio. 
B) Has a below average price-to-earnings ratio. 
C) Has an average price-to-earnings ratio. 
D) May have an above average or below average price-to-earnings ratio.

Question 9

If the random variable of x is normally distributed,____% of all possible observed values of x will be within three standard deviations of the mean.

Accepted Answer

A) 68.26 
B) 95.44 
C) 99.73 
D) 100 
E) None of the above 
A) 68.26 
B) 95.44 
C) 99.73 
D) 100 
E) None of the above

Question 10

An aptitude test has a mean score of 80 and a standard deviation of 5.The population of scores is normally distributed.What proportion of tests has scores over 90?

Accepted Answer

A) .9772 
B) .0228 
C) .9544 
D) .0456 
A) .9772 
B) .0228 
C) .9544 
D) .0456

Question 11

Given 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 12

If the wages of workers for a given company are normally distributed with a mean of $15 per hour,then the proportion of the workers earning more than $13 per hour:

Accepted Answer

A) Is greater than the proportion earning less than $13 per hour. 
B) Is greater than the proportion earning less than $18 per hour. 
C) Is less than 50%. 
D) Is less than the proportion earning more than the mean wage. 
A) Is greater than the proportion earning less than $13 per hour. 
B) Is greater than the proportion earning less than $18 per hour. 
C) Is less than 50%. 
D) Is less than the proportion earning more than the mean wage.

Question 13

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 14

An apple juice producer buys all his apples from a conglomerate of apple growers in one northwest state.The amount of juice squeezed from each of these apples is approximately normally distributed with a mean of 2.25 ounces and a standard deviation of 0.15 ounce. What is the probability that a randomly selected apple will contain between 2.00 and 2.50 ounces?

Accepted Answer

A) .500 
B) .905 
C) .9525 
D) .9544 
A) .500 
B) .905 
C) .9525 
D) .9544

Question 15

What is the probability that a standard normal random variable will be between .3 and 3.2?

Accepted Answer

A) .6179 
B) .3808 
C) .6192 
D) .9987 
A) .6179 
B) .3808 
C) .6192 
D) .9987

Question 16

For a continuous distribution,P(X $\le$ 100)= P(X < 100).

Accepted Answer

A) True 
 B)False

Question 17

During the past six months,73.2% of US households purchased sugar.Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. Find the probability that a household spent more than $16.00

Accepted Answer

A) 1.00 
B) 0.00 
C) 0.50 
D) 0.98 
A) 1.00 
B) 0.00 
C) 0.50 
D) 0.98

Question 18

If the random variable of x is normally distributed,____ % 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 19

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of 0.2 inches. What is the probability that a sheet selected at random will be less than 29.75 inches long?

Accepted Answer

A) .8944 
B) .1056 
C) .9332 
D) .0668 
A) .8944 
B) .1056 
C) .9332 
D) .0668

Question 20

All continuous random variables are normally distributed.

Accepted Answer

A) True 
 B)False

Values of the standard normal random variable are measured

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20.What percentage of the time will the number of boxes received weekly be greater than 200

During the past six months,73.2% of US households purchased sugar.Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.99% of the households spent less than what amount?

For a normal population with a mean of 10 and a variance 4,the P(X $\ge$ 10)is ___.

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 70^th percentile?

A continuous probability distribution having a rectangular shape where the probability is evenly distributed over an interval of numbers is called a uniform probability distribution.

The price-to-earning ratio for firms in a given industry is distributed according to normal distribution.In this industry,a firm with a standard normal variable value of Z = 1:

If the random variable of x is normally distributed,____% of all possible observed values of x will be within three standard deviations of 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 proportion of tests has scores over 90?

Given 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?

If the wages of workers for a given company are normally distributed with a mean of $15 per hour,then the proportion of the workers earning more than $13 per hour:

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

What is the probability that a standard normal random variable will be between .3 and 3.2?

For a continuous distribution,P(X $\le$ 100)= P(X < 100).

During the past six months,73.2% of US households purchased sugar.Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. Find the probability that a household spent more than $16.00

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

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of 0.2 inches. What is the probability that a sheet selected at random will be less than 29.75 inches long?

All continuous random variables are normally distributed.

An Introduction to Business Statistics

Descriptive Statistics: Tabular and Graphical Methods

Descriptive Statistics: Numerical Methods

Probability

Discrete Random Variables

Sampling and 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

Model Building and Model Diagnostics

Time Series Forecasting

Process Improvement Using Control Charts

Nonparametric Methods

Decision Theory

Filters

Exam 6: Continuous Random Variables

Values of the standard normal random variable are measured

A plant manager knows that the number of boxes of supplies received weekly is normally distributed with a mean of 200 and a standard deviation of 20.What percentage of the time will the number of boxes received weekly be greater than 200

During the past six months,73.2% of US households purchased sugar.Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10.99% of the households spent less than what amount?

For a normal population with a mean of 10 and a variance 4,the P(X ≥\ge≥ 10)is ___.

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?

A continuous probability distribution having a rectangular shape where the probability is evenly distributed over an interval of numbers is called a uniform probability distribution.

The price-to-earning ratio for firms in a given industry is distributed according to normal distribution.In this industry,a firm with a standard normal variable value of Z = 1:

If the random variable of x is normally distributed,____% of all possible observed values of x will be within three standard deviations of 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 proportion of tests has scores over 90?

Given 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?

If the wages of workers for a given company are normally distributed with a mean of $15 per hour,then the proportion of the workers earning more than $13 per hour:

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

What is the probability that a standard normal random variable will be between .3 and 3.2?

For a continuous distribution,P(X ≤\le≤ 100)= P(X < 100).

During the past six months,73.2% of US households purchased sugar.Assume that these expenditures are approximately normally distributed with a mean of $8.22 and a standard deviation of $1.10. Find the probability that a household spent more than $16.00

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

The population of lengths of aluminum-coated steel sheets is normally distributed with a mean of 30.05 inches and a standard deviation of 0.2 inches. What is the probability that a sheet selected at random will be less than 29.75 inches long?

All continuous random variables are normally distributed.

An Introduction to Business Statistics

Descriptive Statistics: Tabular and Graphical Methods

Descriptive Statistics: Numerical Methods

Probability

Discrete Random Variables

Sampling and 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

Model Building and Model Diagnostics

Time Series Forecasting

Process Improvement Using Control Charts

Nonparametric Methods

Decision Theory

Filters

For a normal population with a mean of 10 and a variance 4,the P(X $\ge$ 10)is ___.

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 70^th percentile?

For a continuous distribution,P(X $\le$ 100)= P(X < 100).