Question 1

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 2

The time it takes to completely tune an engine of an automobile follows an exponential distribution with a mean of 40 minutes.
a.What is the probability of tuning an engine in 30 minutes or less?
b.What is the probability of tuning an engine between 30 and 35 minutes?

Accepted Answer

The answer of The time it takes to completely tune...

Question 3

Given that Z is a standard normal random variable, what is the value of Z if the are 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

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 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 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 0.9834?

Accepted Answer

A) 0.4834 
B) -2.13 
C) +2.13 
D) zero 
A) 0.4834 
B) -2.13 
C) +2.13 
D) zero

Question 6

The records show that 8% of the items produced by a machine do not meet the specifications. Use the normal approximation to the binomial distribution to answer the following questions. What is the probability that a sample of 100 units contains
a.Five or more defective units?
b.Ten or fewer defective units?
c.Eleven or less defective units?

Accepted Answer

a.0.9015
b

Question 7

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 8

The average life expectancy of computers produced by Ahmadi, Inc. is 6 years with a standard deviation of 10 months. Assume that the lives of computers are normally distributed. Suggestion: For this problem, convert ALL of the units to months.
a.What is the probability that a randomly selected computer will have a life expectancy of at least 7 years?
b.Computers that fail in less than 5years will be replaced free of charge. What percentage of computers are expected to be replaced free of charge?
c.What are the minimum and the maximum life expectancy of the middle 95% of the computers' lives? Give your answers in months and do not round your answers.
d.The company is expecting that only 104 of this year's production will fail in less than 3 years and 8 months. How many computers were produced this year?

Accepted Answer

a.0.1151
b.27.5
c.Mi

Question 9

X is a normally distributed random variable with a mean of 5 and a variance of 4. The probability that X is greater than 10.52 is

Accepted Answer

A) 0.0029 
B) 0.0838 
C) 0.4971 
D) 0.9971 
A) 0.0029 
B) 0.0838 
C) 0.4971 
D) 0.9971

Question 10

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 11

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 12

In a normal distribution, it is known that 27.34% of all the items are included from 100 up to the mean, and another 45.99% of all the items are included from the mean up to 145. Determine the mean and the standard deviation of the distribution.

Accepted Answer

Mean = 113

Question 13

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 14

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 15

The driving time for an individual from his home to his work is uniformly distributed between 300 to 480 seconds.
a.Determine the probability density function.
b.Compute the probability that the driving time will be less than or equal to 435 seconds.
c.Determine the expected driving time.
d.Compute the variance.
e.
Compute the standard deviation.

Accepted Answer

a.b.0.75
c

Question 16

If the mean of a normal distribution is negative,

Accepted Answer

A) the standard deviation must also be negative 
B) the variance must also be negative 
C) a mistake has been made in the computations, because the mean of a normal distribution cannot be negative 
D) None of these alternatives is correct. 
A) the standard deviation must also be negative 
B) the variance must also be negative 
C) a mistake has been made in the computations, because the mean of a normal distribution cannot be negative 
D) None of these alternatives is correct.

Question 17

For a standard normal distribution, the probability of obtaining a z value between -1.9 to 1.7 is

Accepted Answer

A) 0.9267 
B) 0.4267 
C) 1.4267 
D) 0.5000 
A) 0.9267 
B) 0.4267 
C) 1.4267 
D) 0.5000

Question 18

Exhibit 6-5
The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes.
-Refer to Exhibit 6-5. The probability that her trip will take longer than 60 minutes is

Accepted Answer

A) 1.00 
B) 0.40 
C) 0.02 
D) 0.600 
A) 1.00 
B) 0.40 
C) 0.02 
D) 0.600

Question 19

The life expectancy of computer terminals is normally distributed with a mean of 4 years and a standard deviation of 10 months.
a.What is the probability that a randomly selected terminal will last more than 5 years?
b.What percentage of terminals will last between 5 and 6 years?
c.What percentage of terminals will last less than 4 years?
d.What percentage of terminals will last between 2.5 and 4.5 years?
e.
If the manufacturer guarantees the terminals for 3 years (and will replace them if they malfunction), what percentage of terminals will be replaced?

Accepted Answer

a.0.1151
b

Question 20

The daily dinner bills in a local restaurant are normally distributed with a mean of $28 and a standard deviation of $6.
a.What is the probability that a randomly selected bill will be at least $39.10?
b.What percentage of the bills will be less than $16.90?
c.What are the minimum and maximum of the middle 95% of the bills?
d.If twelve of one day's bills had a value of at least $43.06, how many bills did the restaurant collect on that day?

Accepted Answer

a.0.0322
b.0.0322
c.

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

The time it takes to completely tune an engine of an automobile follows an exponential distribution with a mean of 40 minutes. a.What is the probability of tuning an engine in 30 minutes or less? b.What is the probability of tuning an engine between 30 and 35 minutes?

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

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 value of Z if the area to the right of Z is 0.9834?

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

X is a normally distributed random variable with a mean of 5 and a variance of 4. The probability that X is greater than 10.52 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

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

In a normal distribution, it is known that 27.34% of all the items are included from 100 up to the mean, and another 45.99% of all the items are included from the mean up to 145. Determine the mean and the standard deviation of the distribution.

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

If the mean of a normal distribution is negative,

For a standard normal distribution, the probability of obtaining a z value between -1.9 to 1.7 is

Exhibit 6-5 The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes. -Refer to Exhibit 6-5. The probability that her trip will take longer than 60 minutes is

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

Exam 6: Continuous Probability Distributions

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

The time it takes to completely tune an engine of an automobile follows an exponential distribution with a mean of 40 minutes. a.What is the probability of tuning an engine in 30 minutes or less? b.What is the probability of tuning an engine between 30 and 35 minutes?

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

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 value of Z if the area to the right of Z is 0.9834?

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

X is a normally distributed random variable with a mean of 5 and a variance of 4. The probability that X is greater than 10.52 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

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

In a normal distribution, it is known that 27.34% of all the items are included from 100 up to the mean, and another 45.99% of all the items are included from the mean up to 145. Determine the mean and the standard deviation of the distribution.

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

If the mean of a normal distribution is negative,

For a standard normal distribution, the probability of obtaining a z value between -1.9 to 1.7 is

Exhibit 6-5 The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes. -Refer to Exhibit 6-5. The probability that her trip will take longer than 60 minutes is

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

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