Question 1

Exhibit 6-4
f(x) =(1/10) eS1U1P1-x/10S1S1P0 x   0
-Refer to Exhibit 6-4. The probability that x is between 3 and 6 is

Accepted Answer

A) 0.4512 
B) 0.1920 
C) 0.2592 
D) 0.6065 
A) 0.4512 
B) 0.1920 
C) 0.2592 
D) 0.6065

Question 2

Z is a standard normal random variable. Compute the following probabilities.
a.P(-1.33   Z   1.67) 
b.P(1.23   Z   1.55) 
c.P(Z   2.32) 
d.P(Z   -2.08) 
e.P(Z   -1.08)

Accepted Answer

a.0.8607
b

Question 3

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 is the probability that a randomly selected tire will have a life of at least 30,000 miles?

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 4

A major credit card company has determined that its customers charge an average of $280 per month on their accounts with a standard deviation of $20.
a.What percentage of the customers charges more than $275 per month?
b.What percentage of the customers charges less than $243 per month?
c.What percentage of the customers charges between $241 and $301.60 per month?

Accepted Answer

a.59.87%
b

Question 5

A professor at a local university noted that the grades of her students were normally distributed with a mean of 78 and a standard deviation of 10.
a.The professor has informed us that 16.6 percent of her students received grades of A. What is the minimum score needed to receive a grade of A?
b.If 12.1 percent of her students failed the course and received F's, what was the maximum score among those who received an F?
c.If 33 percent of the students received grades of B or better (i.e., A's and B's), what is the minimum score of those who received a B?

Accepted Answer

a.87.7
b.6

Question 6

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 higher 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 7

Given that Z is a standard normal random variable, what is the probability that -2.51   $\le$ Z   F$\le$-1.53?

Accepted Answer

A) 0.4950 
B) 0.4370 
C) 0.0570 
D) 0.9310 
A) 0.4950 
B) 0.4370 
C) 0.0570 
D) 0.9310

Question 8

A random variable X is uniformly distributed between 45 and 150.
a.Determine the probability of X = 48.
b.What is the probability of X   60? 
c.What is the probability of X   50? 
d.Determine the expected vale of X and its standard deviation.

Accepted Answer

a.0.000
b.

Question 9

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 10

Z is a standard normal random variable. The P(1.05 < 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 11

Approximate the following binomial probabilities by the use of normal approximation. Twenty percent of students who finish high school do not go to college. What is the probability that in a sample of 80 high school students
a.exactly 10 will not go to college?
b.70 or more will go to college?
c.fourteen or fewer will not go to college?

Accepted Answer

a.0.0274
b

Question 12

A standard normal distribution is a normal distribution with

Accepted Answer

A) a mean of 1 and a standard deviation of 1 
B) a mean of 0 and a standard deviation of 0 
C) any mean and a standard deviation of 1 
D) any mean and any standard deviation 
A) a mean of 1 and a standard deviation of 1 
B) a mean of 0 and a standard deviation of 0 
C) any mean and a standard deviation of 1 
D) any mean and any standard deviation

Question 13

In a standard normal distribution, the

Accepted Answer

A) mean and the standard deviation are both 1 
B) mean is 0 and the standard deviation is 1 
C) mean is 1 and the standard deviation is 0 
D) mean and the standard deviation can have any value 
A) mean and the standard deviation are both 1 
B) mean is 0 and the standard deviation is 1 
C) mean is 1 and the standard deviation is 0 
D) mean and the standard deviation can have any value

Question 14

Given that Z is a standard normal random variable, what is the probability that Z   -2.12?

Accepted Answer

A) 0.4830 
B) 0.9830 
C) 0.017 
D) 0.966 
A) 0.4830 
B) 0.9830 
C) 0.017 
D) 0.966

Question 15

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 percentage of MBA's will have starting salaries of $34,000 to $46,000?

Accepted Answer

A) 38.49% 
B) 38.59% 
C) 50% 
D) 76.98% 
A) 38.49% 
B) 38.59% 
C) 50% 
D) 76.98%

Question 16

The time it takes a worker on an assembly line to complete a task is exponentially distributed with a mean of 8 minutes.
a.What is the probability density function for the time it takes to complete the task?
b.What is the probability that it will take a worker less than 4 minutes to complete the task?
c.What is the probability that it will take a worker between 6 and 10 minutes to complete the task?

Accepted Answer

a.f(x) =(1

Question 17

For a uniform probability density function,

Accepted Answer

A) the height of the function cannot be larger than one 
B) the height of the function is the same for each value of x 
C) the height of the function is different for various values of x 
D) the height of the function decreases as x increases 
A) the height of the function cannot be larger than one 
B) the height of the function is the same for each value of x 
C) the height of the function is different for various values of x 
D) the height of the function decreases as x increases

Question 18

Given that Z is a standard normal random variable, what is the value of Z if the area to the right of Z is 0.5?

Accepted Answer

A) 0.0000 
B) 1.0000 
C) 0.1915 
D) 0.3413 
A) 0.0000 
B) 1.0000 
C) 0.1915 
D) 0.3413

Question 19

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 20

Given that Z is a standard normal random variable, what is the value of Z if the area between -Z and Z is 0.901?

Accepted Answer

A) 1.96 
B) -1.96 
C) 0.4505 
D)    1.65 
A) 1.96 
B) -1.96 
C) 0.4505 
D)    1.65

Exhibit 6-4 f(x) =(1/10) e^-x/10 x 0 -Refer to Exhibit 6-4. The probability that x is between 3 and 6 is

Z is a standard normal random variable. Compute the following probabilities. a.P(-1.33 Z 1.67) b.P(1.23 Z 1.55) c.P(Z 2.32) d.P(Z -2.08) e.P(Z -1.08)

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 is the probability that a randomly selected tire will have a life of at least 30,000 miles?

A random variable X is uniformly distributed between 45 and 150. a.Determine the probability of X = 48. b.What is the probability of X 60? c.What is the probability of X 50? d.Determine the expected vale of X and its standard deviation.

Z is a standard normal random variable. The P(1.05 < Z < 2.13) equals

A standard normal distribution is a normal distribution with

In a standard normal distribution, the

Given that Z is a standard normal random variable, what is the probability that Z -2.12?

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 percentage of MBA's will have starting salaries of $34,000 to $46,000?

For a uniform probability density function,

Given that Z is a standard normal random variable, what is the value of Z if the area to the right of Z is 0.5?

Given that Z is a standard normal random variable, what is the value of Z if the area between -Z and Z is 0.901?

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

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Index Numbers

Decision Analysis on Website

Sample Survey on Website

Filters

Exam 6: Continuous Probability Distributions

Exhibit 6-4 f(x) =(1/10) e-x/10 x 0 -Refer to Exhibit 6-4. The probability that x is between 3 and 6 is

Z is a standard normal random variable. Compute the following probabilities. a.P(-1.33 Z 1.67) b.P(1.23 Z 1.55) c.P(Z 2.32) d.P(Z -2.08) e.P(Z -1.08)

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 is the probability that a randomly selected tire will have a life of at least 30,000 miles?

Given that Z is a standard normal random variable, what is the probability that -2.51 ≤\le≤ Z F ≤\le≤ -1.53?

A random variable X is uniformly distributed between 45 and 150. a.Determine the probability of X = 48. b.What is the probability of X 60? c.What is the probability of X 50? d.Determine the expected vale of X and its standard deviation.

Z is a standard normal random variable. The P(1.05 < Z < 2.13) equals

A standard normal distribution is a normal distribution with

In a standard normal distribution, the

Given that Z is a standard normal random variable, what is the probability that Z -2.12?

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 percentage of MBA's will have starting salaries of $34,000 to $46,000?

For a uniform probability density function,

Given that Z is a standard normal random variable, what is the value of Z if the area to the right of Z is 0.5?

Given that Z is a standard normal random variable, what is the value of Z if the area between -Z and Z is 0.901?

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

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Regression Analysis: Model Building

Time Series Analysis and Forecasting

Nonparametric Methods

Statistical Methods for Quality Control

Index Numbers

Decision Analysis on Website

Sample Survey on Website

Filters

Exhibit 6-4 f(x) =(1/10) e^-x/10 x 0 -Refer to Exhibit 6-4. The probability that x is between 3 and 6 is