Question 1

A normal distribution with a mean of 0 and a standard deviation of 1 is called

Accepted Answer

A) a probability density function 
B) an ordinary normal curve 
C) a standard normal distribution 
D) None of these alternatives is correct. 
A) a probability density function 
B) an ordinary normal curve 
C) a standard normal distribution 
D) None of these alternatives is correct.

Question 2

Exhibit 6-4
f(x)=(1/10)eS1U1P1-x/10S1S1P0 x    0
-Refer to Exhibit 6-4.The mean of x is

Accepted Answer

A) 0.10 
B) 10 
C) 100 
D) 1,000 
A) 0.10 
B) 10 
C) 100 
D) 1,000

Question 3

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 4

Exhibit 6-8
The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles.
-Refer to Exhibit 6-8.What percentage of tires will have a life of 34,000 to 46,000 miles?

Accepted Answer

A) 38.49% 
B) 76.98% 
C) 50% 
D) 88.49% 
A) 38.49% 
B) 76.98% 
C) 50% 
D) 88.49%

Question 5

Given that Z is a standard normal random variable.What is the value of Z if the area to the right of Z is 0.1401?

Accepted Answer

A) 1.08 
B) 0.1401 
C) 2.16 
D) -1.08 
A) 1.08 
B) 0.1401 
C) 2.16 
D) -1.08

Question 6

Exhibit 6-6
The starting salaries of individuals with an MBA degree are normally distributed with a mean of $40,000 and a standard deviation of $5,000.
-Refer to Exhibit 6-6.What is the probability that a randomly selected individual with an MBA degree will get a starting salary of at least $30,000?

Accepted Answer

A) 0.4772 
B) 0.9772 
C) 0.0228 
D) 0.5000 
A) 0.4772 
B) 0.9772 
C) 0.0228 
D) 0.5000

Question 7

The SAT scores of students are normally distributed with a mean of 950 and a standard deviation of 200.
a.Nancy Bright's SAT score was 1390.What percentage of students have scores more than Nancy Bright?
b.What percentage of students score between 1100 and 1200?
c.What are the minimum and the maximum values of the middle 87.4% of the scores?
d.There were 165 students who scored above 1432.How many students took the SAT?

Accepted Answer

a.1.39%
b.

Question 8

Twenty percent of the employees of a large company are female.Use the normal approximation of the binomial probabilities to answer the following questions.What is the probability that in a random sample of 80 employees
a.exactly 16 will be female?
b.14 or more will be female?
c.15 or fewer will be female?
d.18 or more will be female
e.exactly 17 will be female?

Accepted Answer

a.0.1114
b

Question 9

In a standard normal distribution,the range of values of z is from

Accepted Answer

A) minus infinity to infinity 
B) -1 to 1 
C) 0 to 1 
D) -3.09 to 3.09 
A) minus infinity to infinity 
B) -1 to 1 
C) 0 to 1 
D) -3.09 to 3.09

Question 10

An airline has determined that 20% of its international flights are not on time.Use the normal approximation to the binomial distribution to answer the following questions.What is the probability that of the next 80 international flights
a.Fifteen or less will not be on time?
b.Eighteen or more will not be on time?
c.Exactly 17 will not be on time?

Accepted Answer

a.0.4443
b

Question 11

Exhibit 6-4
f(x)=(1/10)eS1U1P1-x/10S1S1P0 x    0
-Refer to Exhibit 6-4.The probability that x is less than 5 is

Accepted Answer

A) 0.6065 
B) 0.0606 
C) 0.3935 
D) 0.9393 
A) 0.6065 
B) 0.0606 
C) 0.3935 
D) 0.9393

Question 12

The price of a stock is uniformly distributed between $30 and $40.
a.What is the probability that the stock price will be more than $37?
b.What is the probability that the stock price will be less than or equal to $32?
c.What is the probability that the stock price will be between $34 and $38?
d.Determine the expected price of the stock.
e.Determine the standard deviation for the stock price.

Accepted Answer

a.0.3
b.0.

Question 13

The contents of soft drink bottles are normally distributed with a mean of twelve ounces and a standard deviation of one ounce.
a.What is the probability that a randomly selected bottle will contain more than ten ounces of soft drink?
b.What is the probability that a randomly selected bottle will contain between 9.5 and 11 ounces?
c.What percentage of the bottles will contain less than 10.5 ounces of soft drink?

Accepted Answer

a.0.9772
b

Question 14

The salaries of the employees of a corporation are normally distributed with a mean of $25,000 and a standard deviation of $5,000.
a.What is the probability that a randomly selected employee will have a starting salary of at least $31,000?
b.What percentage of employees has salaries of less than $12,200?
c.What are the minimum and the maximum salaries of the middle 95% of the employees?
d.If sixty-eight of the employees have incomes of at least $35,600,how many individuals are employed in the corporation?

Accepted Answer

a.0.1151
b.0.52%
c.m

Question 15

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 16

A value of 0.5 that is added and/or subtracted from a value of x when the continuous normal distribution is used to approximate the discrete binomial distribution is called

Accepted Answer

A) 50% of the area under the normal curve 
B) continuity correction factor 
C) factor of conversion 
D) all of the alternatives are correct answers 
A) 50% of the area under the normal curve 
B) continuity correction factor 
C) factor of conversion 
D) all of the alternatives are correct answers

Question 17

A continuous random variable is uniformly distributed between a and b.The probability density function between a and b is

Accepted Answer

A) zero 
B) (a - b) 
C) (b - a) 
D) 1/(b - a) 
A) zero 
B) (a - b) 
C) (b - a) 
D) 1/(b - a)

Question 18

For a standard normal distribution,the probability of z   0 is

Accepted Answer

A) zero 
B) -0.5 
C) 0.5 
D) one 
A) zero 
B) -0.5 
C) 0.5 
D) one

Question 19

The mean of a standard normal probability distribution

Accepted Answer

A) is always equal to zero 
B) can be any value as long as it is positive 
C) can be any value 
D) is always greater than zero 
A) is always equal to zero 
B) can be any value as long as it is positive 
C) can be any value 
D) is always greater than zero

Question 20

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.Students who made 57.93 or lower on the exam failed the course.What percent of students failed the course?

Accepted Answer

A) 8.53% 
B) 18.53% 
C) 91.47% 
D) 0.853% 
A) 8.53% 
B) 18.53% 
C) 91.47% 
D) 0.853%

A normal distribution with a mean of 0 and a standard deviation of 1 is called

Exhibit 6-4 f(x)=(1/10)e^-x/10 x 0 -Refer to Exhibit 6-4.The mean of x is

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

Exhibit 6-8 The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles. -Refer to Exhibit 6-8.What percentage of tires will have a life of 34,000 to 46,000 miles?

Given that Z is a standard normal random variable.What is the value of Z if the area to the right of Z is 0.1401?

Exhibit 6-6 The starting salaries of individuals with an MBA degree are normally distributed with a mean of $40,000 and a standard deviation of $5,000. -Refer to Exhibit 6-6.What is the probability that a randomly selected individual with an MBA degree will get a starting salary of at least $30,000?

In a standard normal distribution,the range of values of z is from

Exhibit 6-4 f(x)=(1/10)e^-x/10 x 0 -Refer to Exhibit 6-4.The probability that x is less than 5 is

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 value of 0.5 that is added and/or subtracted from a value of x when the continuous normal distribution is used to approximate the discrete binomial distribution is called

A continuous random variable is uniformly distributed between a and b.The probability density function between a and b is

For a standard normal distribution,the probability of z 0 is

The mean of a standard normal probability distribution

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.Students who made 57.93 or lower on the exam failed the course.What percent of students failed the course?

Data and Statistics

Descriptive Statistics: Tabular and Graphical Presentations

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Statistical Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit and Independence

Analysis of Variance and Experimental Design

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Index Numbers

Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters

Exam 6: Continuous Probability Distributions

A normal distribution with a mean of 0 and a standard deviation of 1 is called

Exhibit 6-4 f(x)=(1/10)e-x/10 x 0 -Refer to Exhibit 6-4.The mean of x is

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

Exhibit 6-8 The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles. -Refer to Exhibit 6-8.What percentage of tires will have a life of 34,000 to 46,000 miles?

Given that Z is a standard normal random variable.What is the value of Z if the area to the right of Z is 0.1401?

In a standard normal distribution,the range of values of z is from

Exhibit 6-4 f(x)=(1/10)e-x/10 x 0 -Refer to Exhibit 6-4.The probability that x is less than 5 is

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 value of 0.5 that is added and/or subtracted from a value of x when the continuous normal distribution is used to approximate the discrete binomial distribution is called

A continuous random variable is uniformly distributed between a and b.The probability density function between a and b is

For a standard normal distribution,the probability of z 0 is

The mean of a standard normal probability distribution

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.Students who made 57.93 or lower on the exam failed the course.What percent of students failed the course?

Data and Statistics

Descriptive Statistics: Tabular and Graphical Presentations

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Statistical Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Tests of Goodness of Fit and Independence

Analysis of Variance and Experimental Design

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Index Numbers

Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Decision Analysis

Sample Survey

Filters

Exhibit 6-4 f(x)=(1/10)e^-x/10 x 0 -Refer to Exhibit 6-4.The mean of x is

Exhibit 6-4 f(x)=(1/10)e^-x/10 x 0 -Refer to Exhibit 6-4.The probability that x is less than 5 is