Question 1

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

Question 2

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 3

The Globe Fishery packs shrimp that weigh more than 1.91 ounces each in packages marked" large" and shrimp that weigh less than 0.47 ounces each into packages marked "small"; the remainder are packed in "medium" size packages. If a day's catch showed that 19.77 percent of the shrimp were large and 6.06 percent were small, determine the mean and the standard deviation for the shrimp weights. Assume that the shrimps' weights are normally distributed.

Accepted Answer

Mean = 1.4

Question 4

The monthly earnings of computer programmers are normally distributed with a mean of $4,000. If only 1.7 percent of programmers have monthly incomes of less than $2,834, what is the value of the standard deviation of the monthly earnings of the computer programmers?

Accepted Answer

The answer of The monthly earnings of computer programmers are...

Question 5

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

Question 6

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 7

The prices of condos in a city are normally distributed with a mean of $90,000 and a standard deviation of $28,000.
a.The city government exempts the cheapest 6.68% of the condos from city taxes. What is the maximum price of the condos that will be exempt from city taxes?
b.If 1.79% of the most expensive condos are subject to a luxury tax, what is the minimum price of condos that will be subject to the luxury tax?

Accepted Answer

a.$48,000

Question 8

A continuous probability distribution that is useful in describing the time, or space, between occurrences of an event is a(n)

Accepted Answer

A) normal probability distribution 
B) uniform probability distribution 
C) exponential probability distribution 
D) Poisson probability distribution 
A) normal probability distribution 
B) uniform probability distribution 
C) exponential probability distribution 
D) Poisson probability distribution

Question 9

The ages of students at a university are normally distributed with a mean of 21. What percentage of the student body is at least 21 years old?

Accepted Answer

A) It could be any value, depending on the magnitude of the standard deviation 
B) 50% 
C) 21% 
D) 1.96% 
A) It could be any value, depending on the magnitude of the standard deviation 
B) 50% 
C) 21% 
D) 1.96%

Question 10

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%

Question 11

Approximate the following binomial probabilities by the use of normal approximation.
a.	P(X = 18, n = 50, p = 0.3)
b.	P(X ≥  15, n = 50, p = 0.3)
c.	P(X  ≤ 12, n = 50, p = 0.3)
d.	P(12  ≤ X  ≤ 18, n = 50, p = 0.3)

Accepted Answer

a.0.0805
b

Question 12

A standard normal distribution is a normal distribution

Accepted Answer

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

Question 13

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 14

The random variable x is known to be uniformly distributed between 70 and 90. The probability of x having a value between 80 to 95 is

Accepted Answer

A) 0.75 
B) 0.5 
C) 0.05 
D) 1 
A) 0.75 
B) 0.5 
C) 0.05 
D) 1

Question 15

In grading eggs into small, medium, and large, the Nancy Farms packs the eggs that weigh more than 3.6 ounces in packages marked "large" and the eggs that weigh less than 2.4 ounces into packages marked "small"; the remainder are packed in packages marked "medium." If a day's packaging contained 10.2% large and 4.18% small eggs, determine the mean and the standard deviation for the eggs' weights. Assume that the distribution of the weights is normal.

Accepted Answer

Mean = 3.0

Question 16

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 exactly 47,500 miles?

Accepted Answer

A) 0.0000 
B) 0.9332 
C) 0.0668 
D) 0.4993 
A) 0.0000 
B) 0.9332 
C) 0.0668 
D) 0.4993

Question 17

The weights of items produced by a company are normally distributed with a mean of 4.5 ounces and a standard deviation of 0.3 ounces.
a.What is the probability that a randomly selected item from the production will weigh at least 4.14 ounces?
b.What percentage of the items weigh between 4.8 to 5.04 ounces?
c.Determine the minimum weight of the heaviest 5% of all items produced.
d.If 27,875 of the items of the entire production weigh at least 5.01 ounces, how many items have been produced?

Accepted Answer

a.0.8849
b

Question 18

Z is a standard normal random variable. The P(-1.5 < Z < 1.09) equals

Accepted Answer

A) 0.4322 
B) 0.3621 
C) 0.7953 
D) 0.0711 
A) 0.4322 
B) 0.3621 
C) 0.7953 
D) 0.0711

Question 19

The exponential probability distribution is used with

Accepted Answer

A) a discrete random variable 
B) a continuous random variable 
C) any probability distribution with an exponential term 
D) an approximation of the binomial probability distribution 
A) a discrete random variable 
B) a continuous random variable 
C) any probability distribution with an exponential term 
D) an approximation of the binomial probability distribution

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 0.754?

Accepted Answer

A) 1.16 
B) 1.96 
C) 2.0 
D) 11.6 
A) 1.16 
B) 1.96 
C) 2.0 
D) 11.6

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?

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

The monthly earnings of computer programmers are normally distributed with a mean of $4,000. If only 1.7 percent of programmers have monthly incomes of less than $2,834, what is the value of the standard deviation of the monthly earnings of the computer programmers?

For any continuous random variable, the probability that the random variable takes on exactly a specific value 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 continuous probability distribution that is useful in describing the time, or space, between occurrences of an event is a(n)

The ages of students at a university are normally distributed with a mean of 21. What percentage of the student body is at least 21 years old?

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?

Approximate the following binomial probabilities by the use of normal approximation. a. P(X = 18, n = 50, p = 0.3) b. P(X ≥ 15, n = 50, p = 0.3) c. P(X ≤ 12, n = 50, p = 0.3) d. P(12 ≤ X ≤ 18, n = 50, p = 0.3)

A standard normal distribution is a normal distribution

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

The random variable x is known to be uniformly distributed between 70 and 90. The probability of x having a value between 80 to 95 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 is the probability that a randomly selected tire will have a life of exactly 47,500 miles?

Z is a standard normal random variable. The P(-1.5 < Z < 1.09) equals

The exponential probability distribution is used with

Given that Z is a standard normal random variable. What is the value of Z if the area between -Z and Z is 0.754?

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

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Exam 6: Continuous Probability Distributions

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?

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

The monthly earnings of computer programmers are normally distributed with a mean of $4,000. If only 1.7 percent of programmers have monthly incomes of less than $2,834, what is the value of the standard deviation of the monthly earnings of the computer programmers?

For any continuous random variable, the probability that the random variable takes on exactly a specific value 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 continuous probability distribution that is useful in describing the time, or space, between occurrences of an event is a(n)

The ages of students at a university are normally distributed with a mean of 21. What percentage of the student body is at least 21 years old?

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?

Approximate the following binomial probabilities by the use of normal approximation. a. P(X = 18, n = 50, p = 0.3) b. P(X ≥ 15, n = 50, p = 0.3) c. P(X ≤ 12, n = 50, p = 0.3) d. P(12 ≤ X ≤ 18, n = 50, p = 0.3)

A standard normal distribution is a normal distribution

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

The random variable x is known to be uniformly distributed between 70 and 90. The probability of x having a value between 80 to 95 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 is the probability that a randomly selected tire will have a life of exactly 47,500 miles?

Z is a standard normal random variable. The P(-1.5 < Z < 1.09) equals

The exponential probability distribution is used with

Given that Z is a standard normal random variable. What is the value of Z if the area between -Z and Z is 0.754?

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

Filters