Question 1

Excel's NORM.INV function can be used to compute

Accepted Answer

A) cumulative probabilities for a standard normal z value 
B) the standard normal z value given a cumulative probability 
C) cumulative probabilities for a normally distributed x value 
D) the normally distributed x value given a cumulative probability 
A) cumulative probabilities for a standard normal z value 
B) the standard normal z value given a cumulative probability 
C) cumulative probabilities for a normally distributed x value 
D) the normally distributed x value given a cumulative probability

Question 2

Z is a standard normal random variable. The P(1.41 F1F1F1S1F1F1F10 z F1F1F1S1F1F1F10 2.85) equals

Accepted Answer

A) 0.4772 
B) 0.3413 
C) 0.8285 
D) None of the alternative answers is correct. 
A) 0.4772 
B) 0.3413 
C) 0.8285 
D) None of the alternative answers is correct.

Question 3

Z is a standard normal random variable. What is the value of z if the area to the right of z is 0.9803?

Accepted Answer

A) -2.06 
B) 0.4803 
C) 0.0997 
D) 3.06 
A) -2.06 
B) 0.4803 
C) 0.0997 
D) 3.06

Question 4

For any continuous random variable, the probability that the random variable takes on exactly a specific value is

Accepted Answer

A) 1.00 
B) 0.50 
C) any value between 0 to 1 
D) zero 
A) 1.00 
B) 0.50 
C) any value between 0 to 1 
D) zero

Question 5

The life expectancy of Timely brand watches is normally distributed with a mean of four years and a standard deviation of eight months.
a.What is the probability that a randomly selected watch will be in working condition for more than five years?
b.The company has a three-year warranty period on their watches. What percentage of their watches will be in operating condition after the warranty period?
c.What is the minimum and the maximum life expectancy of the middle 95% of the watches?
d.Ninety-five percent of the watches will have a life expectancy of at least how many months?

Accepted Answer

a.0.0668
b.93.32%
c.Min F1F1F1

Question 6

Exhibit 6-4
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 6-4. What is the random variable in this experiment?

Accepted Answer

A) the starting salaries 
B) the normal distribution 
C) $40,000 
D) $5,000 
A) the starting salaries 
B) the normal distribution 
C) $40,000 
D) $5,000

Question 7

Excel's NORM.S.DIST function can be used to compute

Accepted Answer

A) cumulative probabilities for a standard normal z value 
B) the standard normal z value given a cumulative probability 
C) cumulative probabilities for a normally distributed x value 
D) the normally distributed x value given a cumulative probability 
A) cumulative probabilities for a standard normal z value 
B) the standard normal z value given a cumulative probability 
C) cumulative probabilities for a normally distributed x value 
D) the normally distributed x value given a cumulative probability

Question 8

The average starting salary for this year's graduates of a large community college is $30,000 with a standard deviation of $8,000. Furthermore, it is known that the starting salaries are normally distributed.
a.What is the probability that a randomly selected graduate of this community college will have a starting salary of at least $30,400?
b.Individuals with starting salaries of less than $15,600 receive a low income tax break. What percentage of the graduates will receive the tax break?
c.What are the minimum and the maximum starting salaries of the middle 95% of the graduates?
d.If 303 of the recent graduates have salaries of at least $43,120, how many students graduated this year from this community college?

Accepted Answer

a.0.4801
b.3.59%
c.m

Question 9

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) always has 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) always has a standard deviation of 1

Question 10

Exhibit 6-6
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 6-6. 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) None of the alternative answers is correct. 
A) 38.49% 
B) 76.98% 
C) 50% 
D) None of the alternative answers is correct.

Question 11

The monthly income of residents of Daisy City is normally distributed with a mean of $3000 and a standard deviation of $500.
a.Define the random variable in words.
b.The mayor of Daisy City makes $2,250 a month. What percentage of Daisy City's residents has incomes that are more than the mayor's?
c.Individuals with incomes of less than $1,985 per month are exempt from city taxes. What percentage of residents is exempt from city taxes?
d.What are the minimum and the maximum incomes of the middle 95% of the residents?
e.Two hundred residents have incomes of at least $4,440 per month. What is the population of Daisy City?

Accepted Answer

a.the monthly income of reside

Question 12

"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 and 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.

Question 13

The function that defines the probability distribution of any continuous random variable is a

Accepted Answer

A) normal function 
B) uniform function 
C) Both the normal function and the uniform function are correct. 
D) probability density function 
A) normal function 
B) uniform function 
C) Both the normal function and the uniform function are correct. 
D) probability density function

Question 14

For a standard normal distribution, the probability of obtaining a z value of less than 1.6 is

Accepted Answer

A) 0.1600 
B) 0.0160 
C) 0.0016 
D) 0.9452 
A) 0.1600 
B) 0.0160 
C) 0.0016 
D) 0.9452

Question 15

Exhibit 6-1
Consider the continuous random variable x, which has a uniform distribution over the interval from 20 to 28.
-Refer to Exhibit 6-1. The probability that x will take on a value of at least 26 is

Accepted Answer

A) 0.000 
B) 0.125 
C) 0.250 
D) 1.000 
A) 0.000 
B) 0.125 
C) 0.250 
D) 1.000

Question 16

Scores on a recent national statistics exam were normally distributed with a mean of 80 and a standard deviation of 6.
a.What is the probability that a randomly selected exam will have a score of at least 71?
b.What percentage of exams will have scores between 89 and 92?
c.If the top 2.5% of test scores receive merit awards, what is the lowest score eligible for an award?
d.If there were 334 exams with scores of at least 89, how many students took the exam?

Accepted Answer

a..9332
b.

Question 17

The uniform probability distribution is used with

Accepted Answer

A) a continuous random variable 
B) a discrete random variable 
C) a normally distributed random variable 
D) any random variable 
A) a continuous random variable 
B) a discrete random variable 
C) a normally distributed random variable 
D) any random variable

Question 18

The length of time patients must wait to see a doctor in a local clinic is uniformly distributed between 15 minutes and 2 1/2 hours.
a.Define the random variable in words.
b.What is the probability of a patient waiting exactly 50 minutes?
c.What is the probability that a patient would have to wait between 45 minutes and 2 hours?
d.Compute the probability that a patient would have to wait over 2 hours.
e.Determine the expected waiting time and its standard deviation.

Accepted Answer

a.the length of time

Question 19

For the standard normal probability distribution, the area to the left of the mean is

Accepted Answer

A) -0.5 
B) 0.5 
C) any value between 0 to 1 
D) 1 
A) -0.5 
B) 0.5 
C) any value between 0 to 1 
D) 1

Question 20

Exhibit 6-5
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 6-5. What percentage of items will weigh at least 11.7 ounces?

Accepted Answer

A) 46.78% 
B) 96.78% 
C) 3.22% 
D) 53.22% 
A) 46.78% 
B) 96.78% 
C) 3.22% 
D) 53.22%

Excel's NORM.INV function can be used to compute

Z is a standard normal random variable. The P(1.41  z  2.85) equals

Z is a standard normal random variable. What is the value of z if the area to the right of z is 0.9803?

For any continuous random variable, the probability that the random variable takes on exactly a specific value is

Exhibit 6-4 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 6-4. What is the random variable in this experiment?

Excel's NORM.S.DIST function can be used to compute

A normal probability distribution

Exhibit 6-6 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 6-6. What percentage of tires will have a life of 34,000 to 46,000 miles?

The function that defines the probability distribution of any continuous random variable is a

For a standard normal distribution, the probability of obtaining a z value of less than 1.6 is

Exhibit 6-1 Consider the continuous random variable x, which has a uniform distribution over the interval from 20 to 28. -Refer to Exhibit 6-1. The probability that x will take on a value of at least 26 is

The uniform probability distribution is used with

For the standard normal probability distribution, the area to the left of the mean is

Exhibit 6-5 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 6-5. What percentage of items will weigh at least 11.7 ounces?

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

Comparisons Involving Means, Experimental Design, and Analysis of Variance

Comparisons Involving Proportions and a Test of Independence

Simple Linear Regression

Multiple Regression

Statistical Methods for Quality Control

Time Series Analysis and Forecastng

Filters

Exam 6: Continuous Probability Distributions

Excel's NORM.INV function can be used to compute

Z is a standard normal random variable. The P(1.41  z  2.85) equals

Z is a standard normal random variable. What is the value of z if the area to the right of z is 0.9803?

For any continuous random variable, the probability that the random variable takes on exactly a specific value is

Exhibit 6-4 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 6-4. What is the random variable in this experiment?

Excel's NORM.S.DIST function can be used to compute

A normal probability distribution

Exhibit 6-6 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 6-6. What percentage of tires will have a life of 34,000 to 46,000 miles?

The function that defines the probability distribution of any continuous random variable is a

For a standard normal distribution, the probability of obtaining a z value of less than 1.6 is

Exhibit 6-1 Consider the continuous random variable x, which has a uniform distribution over the interval from 20 to 28. -Refer to Exhibit 6-1. The probability that x will take on a value of at least 26 is

The uniform probability distribution is used with

For the standard normal probability distribution, the area to the left of the mean is

Exhibit 6-5 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 6-5. What percentage of items will weigh at least 11.7 ounces?

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

Comparisons Involving Means, Experimental Design, and Analysis of Variance

Comparisons Involving Proportions and a Test of Independence

Simple Linear Regression

Multiple Regression

Statistical Methods for Quality Control

Time Series Analysis and Forecastng

Filters