Question 1

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 density function has what value in the interval between 20 and 28?

Accepted Answer

A) 0 
B) 0.050 
C) 0.125 
D) 1.000

Question 2

Given that z is a standard normal random variable, what is the value of z if the area to the left of z is 0.9382?

Accepted Answer

A) 1.8 
B) 1.54 
C) 2.1 
D) 1.77

Question 3

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

The answer of The contents of soft drink bottles are...

Question 4

The time between arrivals of customers at the drive-up window of a bank follows an exponential probability distribution with a mean of 10 minutes.
a.What is the probability that the arrival time between customers will be 7 minutes or less?
b.What is the probability that the arrival time between customers will be between 3 and 7 minutes?

Accepted Answer

The answer of The time between arrivals of customers at...

Question 5

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

Accepted Answer

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

Question 6

Exhibit 6-7 
-Refer to Exhibit 6-7. The mean of x is

Accepted Answer

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

Question 7

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.

Question 8

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

Question 9

There is a lower limit but no upper limit for a random variable that follows the

Accepted Answer

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

Question 10

For a uniform probability density function, the height of the function

Accepted Answer

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

Question 11

Exhibit 6-7 
-The time it takes to hand carve a guitar neck is uniformly distributed between 110 and 190 minutes.
a.What is the probability that a guitar neck can be carved between 95 and 165 minutes?
b.What is the probability that the guitar neck can be carved between 120 and 200 minutes?
c.Determine the expected completion time for carving the guitar neck.
d.Compute the standard deviation.

Accepted Answer

The answer of Exhibit 6-7 
-The time it takes to...

Question 12

Excel's EXPON.DIST function can be used to compute

Accepted Answer

A) exponents 
B) exponential probabilities 
C) cumulative exponential probabilities 
D) Both exponential probabilities and cumulative exponential probabilities are correct.

Question 13

The time at which the mailman delivers the mail to Ace Bike Shop follows a normal distribution with mean 2:00 PM and standard deviation of 15 minutes.
a. What is the probability the mail will arrive after 2:30 PM?
b. What is the probability the mail will arrive before 1:36 PM?
c. What is the probability the mail will arrive between 1:48 PM and 2:09 PM?

Accepted Answer

The answer of The time at which the mailman delivers...

Question 14

The mean of a standard normal probability distribution

Accepted Answer

A) is always equal to 1 
B) can be any value as long as it is positive 
C) can be any value 
D) None of the alternative answers is correct.

Question 15

The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability of assembling the product in 7 minutes or more is

Accepted Answer

A) 0.25 
B) 0.75 
C) zero 
D) 1

Question 16

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

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)

Question 18

X is a normally distributed random variable with a mean of 22 and a standard deviation of 5. The probability that x is less than 9.7 is

Accepted Answer

A) 0.000 
B) 0.4931 
C) 0.0069 
D) 0.9931

Question 19

Exhibit 6-7 
-All of the following distributions are symmetric except

Accepted Answer

A) uniform 
B) normal 
C) exponential 
D) standard normal

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 is the probability that a randomly selected item will weigh between 11 and 12 ounces?

Accepted Answer

A) 0.4772 
B) 0.4332 
C) 0.9104 
D) 0.0440

Exam 6: Continuous Probability Distributions

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 density function has what value in the interval between 20 and 28?

Given that z is a standard normal random variable, what is the value of z if the area to the left of z is 0.9382?

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

Exhibit 6-7 -Refer to Exhibit 6-7. The mean of x is

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?