Question 1

Z is a standard normal random variable. The PZ ≥ 2.11) equals

Accepted Answer

A)  0.4821 
B)  0.9821 
C)  0.5 
D)  0.0174 
A)  0.4821 
B)  0.9821 
C)  0.5 
D)  0.0174

Question 2

When a continuous probability distribution is used to approximate a discrete probability distribution

Accepted Answer

A)  a value of 0.5 is added and/or subtracted from the area 
B)  a value of 0.5 is added and/or subtracted from the value of x 
C)  a value of 0.5 is added to the area 
D)  a value of 0.5 is subtracted from the area 
A)  a value of 0.5 is added and/or subtracted from the area 
B)  a value of 0.5 is added and/or subtracted from the value of x 
C)  a value of 0.5 is added to the area 
D)  a value of 0.5 is subtracted from the area

Question 3

Exhibit 6-9
The average price of personal computers manufactured by MNM Company is $1,200 with a standard deviation of
$220. Furthermore, it is known that the computer prices manufactured by MNM are normally distributed.
-Refer to Exhibit 6-9. Computers with prices of more than $1,750 receive a discount. What percentage of the computers will receive the discount?

Accepted Answer

A)  62% 
B)  0.62% 
C)  0.062% 
D)  99.38% 
A)  62% 
B)  0.62% 
C)  0.062% 
D)  99.38%

Question 4

Exhibit 6-1
The assembly time for a product is uniformly distributed between 6 to 10 minutes.
-Refer to Exhibit 6-1. The probability of assembling the product between 7 to 9 minutes is

Accepted Answer

A)  zero 
B)  0.50 
C)  0.20 
D)  1 
A)  zero 
B)  0.50 
C)  0.20 
D)  1

Question 5

Exhibit 6-9
The average price of personal computers manufactured by MNM Company is $1,200 with a standard deviation of
$220. Furthermore, it is known that the computer prices manufactured by MNM are normally distributed.
-Refer to Exhibit 6-9. If 513 of the MNM computers were priced at or below $647.80, how many computers were produced by MNM?

Accepted Answer

A)  185,500 
B)  85,500 
C)  513,000 
D)  not enough information is provided to answer this question 
A)  185,500 
B)  85,500 
C)  513,000 
D)  not enough information is provided to answer this question

Question 6

Exhibit 6-2
The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds.
-Refer to Exhibit 6-2. The probability of a player weighing more than 241.25 pounds is

Accepted Answer

A)  0.4505 
B)  0.0495 
C)  0.9505 
D)  0.9010 
A)  0.4505 
B)  0.0495 
C)  0.9505 
D)  0.9010

Question 7

Z is a standard normal random variable. The P1.05 ≤ Z ≤ 2.13) equals

Accepted Answer

A)  0.8365 
B)  0.1303 
C)  0.4834 
D)  0.3531 
A)  0.8365 
B)  0.1303 
C)  0.4834 
D)  0.3531

Question 8

Exhibit 6-1
The assembly time for a product is uniformly distributed between 6 to 10 minutes.
-Refer to Exhibit 6-1. The probability density function has what value in the interval between 6 and 10?

Accepted Answer

A)  0.25 
B)  4.00 
C)  5.00 
D)  zero 
A)  0.25 
B)  4.00 
C)  5.00 
D)  zero

Question 9

Exhibit 6-7
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces.
-Refer to Exhibit 6-7. What percentage of items will weigh between 6.4 and 8.9 ounces?

Accepted Answer

A)  0.1145 
B)  0.2881 
C)  0.1736 
D)  0.4617 
A)  0.1145 
B)  0.2881 
C)  0.1736 
D)  0.4617

Question 10

A normal probability distribution

Accepted Answer

A)  is a continuous probability distribution 
B)  is a discrete probability distribution 
C)  can be either continuous or discrete 
D)  must have a standard deviation of 1 
A)  is a continuous probability distribution 
B)  is a discrete probability distribution 
C)  can be either continuous or discrete 
D)  must have a standard deviation of 1

Question 11

Exhibit 6-10
A professor at a local university noted that the grades of her students were normally distributed with a mean of 73 and a standard deviation of 11.
-Refer to Exhibit 6-10. If 69.5 percent of the students received grades of C or better, what is the minimum score of those who received C's?

Accepted Answer

A)  70.39 
B)  67.39 
C)  50.39 
D)  65.39 
A)  70.39 
B)  67.39 
C)  50.39 
D)  65.39

Question 12

Z is a standard normal random variable. The P 1.20 ≤ Z ≤ 1.85) equals

Accepted Answer

A)  0.4678 
B)  0.3849 
C)  0.8527 
D)  0.0829 
A)  0.4678 
B)  0.3849 
C)  0.8527 
D)  0.0829

Question 13

The salaries at a corporation are normally distributed with an average salary of $19,000 and a standard deviation of
$4,000.
a. What is the probability that an employee will have a salary between $12,520 and $13,480?
b. What is the probability that an employee will have a salary more than $11,880?
c. What is the probability that an employee will have a salary less than $28,440?

Accepted Answer

a. 0.0312

Question 14

Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sample of 12 names is called on a Monday, what is the probability that four students are absent?

Accepted Answer

A)  0.0683 
B)  0.0213 
C)  0.0021 
D)  0.1329 
A)  0.0683 
B)  0.0213 
C)  0.0021 
D)  0.1329

Question 15

"DRUGS R US" is a large manufacturer of various kinds of liquid vitamins. The quality control department has noted that the bottles of vitamins marked 6 ounces vary in content with a standard deviation of 0.3 ounces. Assume the contents of the bottles are normally distributed.
a. What percentage of all bottles produced contains more than 6.51 ounces of vitamins?
b. What percentage of all bottles produced contains less than 5.415 ounces?
c. What percentage of bottles produced contains between 5.46 to 6.495 ounces?
d. Ninety-five percent of the bottles will contain at least how many ounces?
e. What percentage of the bottles contains between 6.3 and 6.6 ounces?

Accepted Answer

a. 4.46%
b. 2.56%
c.

Question 16

The average life expectancy of dishwashers produced by a company is 6 years with a standard deviation of 8 month Assume that the lives of dishwashers are normally distributed.
a. What is the probability that a randomly selected dishwasher will have a life expectancy of at least 7 years?
b. Dishwashers that fail operating in less than 4 1/2 years will be replaced free of charge. What percent of dishwashers are expected to be replaced free of charge?
c. What are the minimum and the maximum life expectancy of the middle 95% of the dishwashers' lives? Give your answer in months.
d. If 155 of this year's dishwasher production fail operating in less than 4 years and 4 months, how many dishwashers were produced this year?

Accepted Answer

a. 0.0668
b. 1.22%
c

Question 17

A uniform probability distribution is a continuous probability distribution where the probability that the random variable assumes a value in any interval of equal length is

Accepted Answer

A)  different for each interval 
B)  the same for each interval 
C)  at least one 
D)  None of these alternatives is correct. 
A)  different for each interval 
B)  the same for each interval 
C)  at least one 
D)  None of these alternatives is correct.

Question 18

Exhibit 6-7
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces.
-Refer to Exhibit 6-7. What is the probability that a randomly selected item weighs exactly 8 ounces?

Accepted Answer

A)  0.5 
B)  1.0 
C)  0.3413 
D)  0.0000 
A)  0.5 
B)  1.0 
C)  0.3413 
D)  0.0000

Question 19

X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that X is between 1.48 and 15.56 is

Accepted Answer

A)  0.0222 
B)  0.4190 
C)  0.5222 
D)  0.9190 
A)  0.0222 
B)  0.4190 
C)  0.5222 
D)  0.9190

Question 20

Given that Z is a standard normal random variable, what is the value of Z if the area to the left of Z is 0.0559?

Accepted Answer

A)  0.4441 
B)  1.59 
C)  0.0000 
D)  1.50 
A)  0.4441 
B)  1.59 
C)  0.0000 
D)  1.50

Z is a standard normal random variable. The PZ ≥ 2.11) equals

When a continuous probability distribution is used to approximate a discrete probability distribution

Exhibit 6-1 The assembly time for a product is uniformly distributed between 6 to 10 minutes. -Refer to Exhibit 6-1. The probability of assembling the product between 7 to 9 minutes is

Exhibit 6-2 The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds. -Refer to Exhibit 6-2. The probability of a player weighing more than 241.25 pounds is

Z is a standard normal random variable. The P1.05 ≤ Z ≤ 2.13) equals

Exhibit 6-1 The assembly time for a product is uniformly distributed between 6 to 10 minutes. -Refer to Exhibit 6-1. The probability density function has what value in the interval between 6 and 10?

Exhibit 6-7 The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. -Refer to Exhibit 6-7. What percentage of items will weigh between 6.4 and 8.9 ounces?

A normal probability distribution

Z is a standard normal random variable. The P 1.20 ≤ Z ≤ 1.85) equals

Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sample of 12 names is called on a Monday, what is the probability that four students are absent?

A uniform probability distribution is a continuous probability distribution where the probability that the random variable assumes a value in any interval of equal length is

Exhibit 6-7 The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. -Refer to Exhibit 6-7. What is the probability that a randomly selected item weighs exactly 8 ounces?

X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that X is between 1.48 and 15.56 is

Given that Z is a standard normal random variable, what is the value of Z if the area to the left of Z is 0.0559?

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Comparisons Involving Means, Experimental Design, and Analysis of Variance

Comparisons Involving Proportions and a Test of Independence

Simple Linear Regression

Multiple Regression

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Exam 6: Continuous Probability Distributions

Z is a standard normal random variable. The PZ ≥ 2.11) equals

When a continuous probability distribution is used to approximate a discrete probability distribution

Exhibit 6-1 The assembly time for a product is uniformly distributed between 6 to 10 minutes. -Refer to Exhibit 6-1. The probability of assembling the product between 7 to 9 minutes is

Exhibit 6-2 The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds. -Refer to Exhibit 6-2. The probability of a player weighing more than 241.25 pounds is

Z is a standard normal random variable. The P1.05 ≤ Z ≤ 2.13) equals

Exhibit 6-1 The assembly time for a product is uniformly distributed between 6 to 10 minutes. -Refer to Exhibit 6-1. The probability density function has what value in the interval between 6 and 10?

Exhibit 6-7 The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. -Refer to Exhibit 6-7. What percentage of items will weigh between 6.4 and 8.9 ounces?

A normal probability distribution

Z is a standard normal random variable. The P 1.20 ≤ Z ≤ 1.85) equals

Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sample of 12 names is called on a Monday, what is the probability that four students are absent?

A uniform probability distribution is a continuous probability distribution where the probability that the random variable assumes a value in any interval of equal length is

Exhibit 6-7 The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces. -Refer to Exhibit 6-7. What is the probability that a randomly selected item weighs exactly 8 ounces?

X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that X is between 1.48 and 15.56 is

Given that Z is a standard normal random variable, what is the value of Z if the area to the left of Z is 0.0559?

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Comparisons Involving Means, Experimental Design, and Analysis of Variance

Comparisons Involving Proportions and a Test of Independence

Simple Linear Regression

Multiple Regression

Filters