Question 1

Exhibit 6-7  
-Refer to Exhibit 6-7. 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

X is a normally distributed random variable with a mean of 12 and a standard deviation of 3. The probability that x equals 19.62 is

Accepted Answer

A) 0.000 
B) 0.0055 
C) 0.4945 
D) 0.9945 
A) 0.000 
B) 0.0055 
C) 0.4945 
D) 0.9945

Question 3

A continuous random variable may assume

Accepted Answer

A) all values in an interval or collection of intervals 
B) only integer values in an interval or collection of intervals 
C) only fractional values in an interval or collection of intervals 
D) all the positive integer values in an interval 
A) all values in an interval or collection of intervals 
B) only integer values in an interval or collection of intervals 
C) only fractional values in an interval or collection of intervals 
D) all the positive integer values in an interval

Question 4

The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability density function has what value in the interval between 6 and 10?

Accepted Answer

A) 0.25 
B) 4.00 
C) 5.00 
D) zero 
A) 0.25 
B) 4.00 
C) 5.00 
D) zero

Question 5

Exhibit 6-7  
-A property of the exponential distribution is that the mean equals the

Accepted Answer

A) mode 
B) median 
C) variance 
D) standard deviation 
A) mode 
B) median 
C) variance 
D) standard deviation

Question 6

Exhibit 6-3
The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds.
-Refer to Exhibit 6-3. What percent of players weigh between 180 and 220 pounds?

Accepted Answer

A) 34.13% 
B) 68.26% 
C) 0.3413% 
D) None of the alternative answers is correct. 
A) 34.13% 
B) 68.26% 
C) 0.3413% 
D) None of the alternative answers is correct.

Question 7

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

Accepted Answer

a.0.8607
b

Question 8

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% of her students received grades of A. What is the minimum score needed to receive a grade of A?
b.If 12.1% of her students failed the course and received Fs, what was the maximum score among those who received an F?
c.If 33% of the students received grades of B or better (i.e., As and Bs), what is the minimum score of those who received a B?

Accepted Answer

a.87.7
b.6

Question 9

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 10

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 are 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.

Question 11

The mean, median, and mode have the same value for which of the following probability distributions?

Accepted Answer

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

Question 12

A standard normal distribution is a normal distribution with

Accepted Answer

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

Question 13

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 14

In a standard normal distribution, the range of values of z is from

Accepted Answer

A) minus infinity to infinity 
B) -1 to 1 
C) 0 to 1 
D) -3.09 to 3.09 
A) minus infinity to infinity 
B) -1 to 1 
C) 0 to 1 
D) -3.09 to 3.09

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 variance of x is approximately

Accepted Answer

A) 2.309 
B) 5.333 
C) 32 
D) 0.667 
A) 2.309 
B) 5.333 
C) 32 
D) 0.667

Question 16

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 17

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 18

The life expectancy of point-of-sale (POS) 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 19

The probability distribution that can be described by just one parameter is the

Accepted Answer

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

Question 20

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) Either a or b could be correct depending on the magnitude of the standard deviation. 
D) None of the alternative answers is correct. 
A) different for each interval 
B) the same for each interval 
C) Either a or b could be correct depending on the magnitude of the standard deviation. 
D) None of the alternative answers is correct.

Exhibit 6-7 -Refer to Exhibit 6-7. The probability that x is between 3 and 6 is

X is a normally distributed random variable with a mean of 12 and a standard deviation of 3. The probability that x equals 19.62 is

A continuous random variable may assume

The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability density function has what value in the interval between 6 and 10?

Exhibit 6-7 -A property of the exponential distribution is that the mean equals the

Exhibit 6-3 The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds. -Refer to Exhibit 6-3. What percent of players weigh between 180 and 220 pounds?

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

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

The mean, median, and mode have the same value for which of the following probability distributions?

A standard normal distribution is a normal distribution with

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

In a standard normal distribution, the range of values of z is from

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 variance of x is approximately

A normal probability distribution

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

The probability distribution that can be described by just one parameter is the

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

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

Tests of Goodness of Fit, Independence and Multiple Proportions

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

Decision Analysis

Sample Survey

Filters

Exam 6: Continuous Probability Distributions

Exhibit 6-7 -Refer to Exhibit 6-7. The probability that x is between 3 and 6 is

X is a normally distributed random variable with a mean of 12 and a standard deviation of 3. The probability that x equals 19.62 is

A continuous random variable may assume

The assembly time for a product is uniformly distributed between 6 to 10 minutes. The probability density function has what value in the interval between 6 and 10?

Exhibit 6-7 -A property of the exponential distribution is that the mean equals the

Exhibit 6-3 The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds. -Refer to Exhibit 6-3. What percent of players weigh between 180 and 220 pounds?

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

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

The mean, median, and mode have the same value for which of the following probability distributions?

A standard normal distribution is a normal distribution with

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

In a standard normal distribution, the range of values of z is from

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 variance of x is approximately

A normal probability distribution

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

The probability distribution that can be described by just one parameter is the

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

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

Tests of Goodness of Fit, Independence and Multiple Proportions

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

Decision Analysis

Sample Survey

Filters

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