Question 1

If the random variable X has a mean of µ and a standard deviation σ,then the mean and standard deviation,respectively,of (X − µ)/σ are

Accepted Answer

A)  μ and σ. 
B) 
And s. 
C)  1 and 0. 
D)  0 and 1. 
A)  μ and σ. 
B) 
And s. 
C)  1 and 0. 
D)  0 and 1. D

Question 2

The grade a student received on an examination was transformed to a z value,which was negative.Therefore,we know that he scored

Accepted Answer

A)  higher than 16 percent of the class. 
B)  higher than 45 percent of the class. 
C)  above the first quartile. 
D)  below the mean. 
E)  lower than 16 percent of the class. 
A)  higher than 16 percent of the class. 
B)  higher than 45 percent of the class. 
C)  above the first quartile. 
D)  below the mean. 
E)  lower than 16 percent of the class. D

Question 3

For a continuous distribution,the exact probability of a particular value is zero.

Accepted Answer

A) True 
 B)False  True

Question 4

A uniform distribution f(x)is a continuous probability distribution,which says the probability that x is in any 2 intervals of equal length is the same.

Accepted Answer

A) True 
 B)False

Question 5

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 6

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 7

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

Accepted Answer

A) True 
 B)False

Question 8

For a binomial probability experiment,with n = 150 and p = .2,it is appropriate to use the normal approximation to the binomial distribution.

Accepted Answer

A) True 
 B)False

Question 9

It is appropriate to use the uniform distribution to describe a continuous random variable x when

Accepted Answer

A)  the area under the probability curve = 1. 
B)  the probability curve f(x)> 0. 
C)  the shape of the histogram of all possible values of x is nonsymmetrical. 
D)  relative frequencies of all possible values of x are about the same. 
A)  the area under the probability curve = 1. 
B)  the probability curve f(x)> 0. 
C)  the shape of the histogram of all possible values of x is nonsymmetrical. 
D)  relative frequencies of all possible values of x are about the same.

Question 10

Which of the following is a continuous distribution?

Accepted Answer

A)  Poisson 
B)  hypergeometric 
C)  exponential 
D)  binomial 
A)  Poisson 
B)  hypergeometric 
C)  exponential 
D)  binomial

Question 11

For a continuous distribution,P(X £ 100)= P(X < 100).

Accepted Answer

A) True 
 B)False

Question 12

The fill weight of a certain brand of adult cereal is normally distributed with a mean of 910 grams and a standard deviation of 5 grams.We calculated the value of z for a specific box of this brand of cereal,and the z value was negative.This negative z value indicates that

Accepted Answer

A)  we made a mistake in our calculations,as z must always be a nonnegative number. 
B)  the fill weight exceeds 910 grams. 
C)  the fill weight is less than 910 grams. 
D)  the fill weight is equal to 910 grams. 
E)  the fill weight may be more or less than 910 grams depending on the value of the standard deviation. 
A)  we made a mistake in our calculations,as z must always be a nonnegative number. 
B)  the fill weight exceeds 910 grams. 
C)  the fill weight is less than 910 grams. 
D)  the fill weight is equal to 910 grams. 
E)  the fill weight may be more or less than 910 grams depending on the value of the standard deviation.

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

In order to approximate the binomial distribution using the normal distribution,the following condition(s)must be met if p is near 1.

Accepted Answer

A)  np > 5 only 
B)  n must be larger than just meeting the condition of np > 5. 
C)  n can be as small as np > 5. 
D)  n > 5 
A)  np > 5 only 
B)  n must be larger than just meeting the condition of np > 5. 
C)  n can be as small as np > 5. 
D)  n > 5

Question 15

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.

Question 16

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

Accepted Answer

A) True 
 B)False

Question 17

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 percent. 
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 percent. 
D)  is less than the proportion earning more than the mean wage.

Question 18

The normal approximation of the binomial distribution is appropriate when

Accepted Answer

A)  np ≥ 5. 
B)  n(1 − p)≥ 5. 
C)  np ≤ 5. 
D)  n(1 − p)≤ 5 and np ≤ 5. 
E)  np ≥ 5 and n(1 − p)≥ 5. 
A)  np ≥ 5. 
B)  n(1 − p)≥ 5. 
C)  np ≤ 5. 
D)  n(1 − p)≤ 5 and np ≤ 5. 
E)  np ≥ 5 and n(1 − p)≥ 5.

Question 19

If the random variable x is normally distributed,68.26 percent of all possible observed values of x will be within two standard deviations of the mean.

Accepted Answer

A) True 
 B)False

Question 20

A standard normal distribution has a mean of ____________ and standard deviation of ____________.

Accepted Answer

A)  zero,zero 
B)  zero,one 
C)  one,one 
D)  one,zero 
A)  zero,zero 
B)  zero,one 
C)  one,one 
D)  one,zero

If the random variable X has a mean of µ and a standard deviation σ,then the mean and standard deviation,respectively,of (X − µ)/σ are

The grade a student received on an examination was transformed to a z value,which was negative.Therefore,we know that he scored

For a continuous distribution,the exact probability of a particular value is zero.

A uniform distribution f(x)is a continuous probability distribution,which says the probability that x is in any 2 intervals of equal length is the same.

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 first step to constructing a normal probability plot is to

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

For a binomial probability experiment,with n = 150 and p = .2,it is appropriate to use the normal approximation to the binomial distribution.

It is appropriate to use the uniform distribution to describe a continuous random variable x when

Which of the following is a continuous distribution?

For a continuous distribution,P(X £ 100)= P(X < 100).

The fill weight of a certain brand of adult cereal is normally distributed with a mean of 910 grams and a standard deviation of 5 grams.We calculated the value of z for a specific box of this brand of cereal,and the z value was negative.This negative z value indicates that

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

In order to approximate the binomial distribution using the normal distribution,the following condition(s)must be met if p is near 1.

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

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

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 normal approximation of the binomial distribution is appropriate when

If the random variable x is normally distributed,68.26 percent of all possible observed values of x will be within two standard deviations of the mean.

A standard normal distribution has a mean of and standard deviation of .

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 for Means and Proportions

Statistical Inferences for Population Variances

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression and Model Building

Time Series Forecasting and Index Numbers

Nonparametric Methods

Decision Theory

Filters

Exam 6: Continuous Random Variables

If the random variable X has a mean of µ and a standard deviation σ,then the mean and standard deviation,respectively,of (X − µ)/σ are

The grade a student received on an examination was transformed to a z value,which was negative.Therefore,we know that he scored

For a continuous distribution,the exact probability of a particular value is zero.

A uniform distribution f(x)is a continuous probability distribution,which says the probability that x is in any 2 intervals of equal length is the same.

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 first step to constructing a normal probability plot is to

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

For a binomial probability experiment,with n = 150 and p = .2,it is appropriate to use the normal approximation to the binomial distribution.

It is appropriate to use the uniform distribution to describe a continuous random variable x when

Which of the following is a continuous distribution?

For a continuous distribution,P(X £ 100)= P(X < 100).

The fill weight of a certain brand of adult cereal is normally distributed with a mean of 910 grams and a standard deviation of 5 grams.We calculated the value of z for a specific box of this brand of cereal,and the z value was negative.This negative z value indicates that

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

In order to approximate the binomial distribution using the normal distribution,the following condition(s)must be met if p is near 1.

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

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

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 normal approximation of the binomial distribution is appropriate when

If the random variable x is normally distributed,68.26 percent of all possible observed values of x will be within two standard deviations of the mean.

A standard normal distribution has a mean of ____________ and standard deviation of ____________.

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 for Means and Proportions

Statistical Inferences for Population Variances

Experimental Design and Analysis of Variance

Chi-Square Tests

Simple Linear Regression Analysis

Multiple Regression and Model Building

Time Series Forecasting and Index Numbers

Nonparametric Methods

Decision Theory

Filters

A standard normal distribution has a mean of and standard deviation of .