Question 1

The number of defects manufactured by workers in a small engine plant is an example of a discrete random variable.

Accepted Answer

A) True 
 B)False

Question 2

If a continuous random variable is said to be exponentially distributed,what would be the easiest way to reduce the standard deviation?

Accepted Answer

The standard deviation of an e

Question 3

For a standardized normal distribution,calculate P(1.78 < z < 2.34).

Accepted Answer

A) 0.0124 
B) 0.0341 
C) 0.0412 
D) 0.0279 
A) 0.0124 
B) 0.0341 
C) 0.0412 
D) 0.0279

Question 4

A random variable is normally distributed with a mean of 25 and a standard deviation of 5.If an observation is randomly selected from the distribution,what value will be exceeded 85% of the time?

Accepted Answer

A) 16.2 
B) 17.9 
C) 19.8 
D) 14.2 
A) 16.2 
B) 17.9 
C) 19.8 
D) 14.2

Question 5

All symmetric distributions can be assumed normally distributed.

Accepted Answer

A) True 
 B)False

Question 6

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25.Based on this information,what is the probability that a specific fare will exceed $15.00?

Accepted Answer

Since this is a normal distribution prob

Question 7

For a standardized normal distribution,determine a value,say z0,so that P(z ≤ z0)= 0.01.

Accepted Answer

A) -2.33 
B) -1.96 
C) 2.33 
D) 1.96 
A) -2.33 
B) -1.96 
C) 2.33 
D) 1.96

Question 8

The amount of drying time for the paint applied to a plastic component part is thought to be uniformly distributed between 30 and 60 minutes.Currently,the automated process selects the part from the drying bin after the part has been there for 50 minutes.Based on this,the probability that a part selected will not be dry is approximately 0.33.

Accepted Answer

A) True 
 B)False

Question 9

Consider a random variable,z,that has a standardized normal distribution.Determine P(z > 1.645).

Accepted Answer

A) 0.05 
B) 0.01 
C) 0.03 
D) 0.45 
A) 0.05 
B) 0.01 
C) 0.03 
D) 0.45

Question 10

For the normal distribution with parameters μ = 0,σ = 3;calculate P(x > 1).

Accepted Answer

A) 0.5812 
B) 0.1214 
C) 0.3707 
D) 0.4412 
A) 0.5812 
B) 0.1214 
C) 0.3707 
D) 0.4412

Question 11

The Varden Packaging Company has a contract to fill 50-gallon barrels with gasoline for use by the U.S.Army.The machine that Varden uses has an adjustable device that allows the average fill per barrel to be adjusted as desired.However,the actual distribution of fill volume from the machine is known to be normally distributed with a standard deviation equal to 0.5 gallons.The contract that Varden has with the military calls for no more than 2 percent of all barrels to contain less than 49.2 gallons of gasoline.Suppose Varden managers are unwilling to set the mean fill at any level higher than 50 gallons.Given that,in order to meet the requirements,they will need to increase the standard deviation of fill volume.

Accepted Answer

A) True 
 B)False

Question 12

A major cell phone service provider has determined that the number of minutes that its customers use their phone per month is normally distributed with a mean equal to 445.5 minutes with a standard deviation equal to 177.8 minutes.The company is thinking of charging a lower rate for customers who use the phone less than a specified amount.If it wishes to give the rate reduction to no more than 12 percent of its customers,what should the cut-off be?

Accepted Answer

A) About 237 minutes 
B) About 654 minutes 
C) About 390 minutes 
D) About 325 minutes 
A) About 237 minutes 
B) About 654 minutes 
C) About 390 minutes 
D) About 325 minutes

Question 13

Consider a random variable,z,that has a standardized normal distribution.Determine P(0 < z < 1.96).

Accepted Answer

A) 0.1250 
B) 0.5250 
C) 0.3250 
D) 0.4750 
A) 0.1250 
B) 0.5250 
C) 0.3250 
D) 0.4750

Question 14

For the normal distribution with parameters μ = 5,σ= 2;calculate P(0 < x < 8).

Accepted Answer

A) 0.8023 
B) 0.4152 
C) 0.9270 
D) 0.8845 
A) 0.8023 
B) 0.4152 
C) 0.9270 
D) 0.8845

Question 15

A continuous random variable approaches normality as the level of skewness increases.

Accepted Answer

A) True 
 B)False

Question 16

The manager of a computer help desk operation has collected enough data to conclude that the distribution of time per call is normally distributed with a mean equal to 8.21 minutes and a standard deviation of 2.14 minutes.Based on this,what is the probability that a call will last longer than 13 minutes?

Accepted Answer

A) About 0.0125 
B) Approximately 0.4875 
C) About 0.5125 
D) About 0.9875 
A) About 0.0125 
B) Approximately 0.4875 
C) About 0.5125 
D) About 0.9875

Question 17

Assuming that the change in daily closing prices for stocks on the New York Stock Exchange is a random variable that is normally distributed with a mean of $0.35 and a standard deviation of $0.33.Based on this information,what is the probability that a randomly selected stock will be lower by $0.40 or more?

Accepted Answer

A) 2.27 
B) 0.4884 
C) 0.0116 
D) 0.9884 
A) 2.27 
B) 0.4884 
C) 0.0116 
D) 0.9884

Question 18

It is assumed that the time customers spend in a record store is uniformly distributed between 3 and 12 minutes.Based on this information,what is the probability that a customer will spend more than 9 minutes in the record store?

Accepted Answer

A) 0.33 
B) 0.1111 
C) 0.67 
D) 0.25 
A) 0.33 
B) 0.1111 
C) 0.67 
D) 0.25

Question 19

A study of cars arriving at a parking structure at the local airport shows that the time between arrivals is 1.2 minutes and is exponentially distributed.Based on this information,the mean number of cars arriving per minute is about 0.83.

Accepted Answer

A) True 
 B)False

Question 20

A store sells 6 different models of cell phones and have found that they sell an equal number of each model.The probability distribution that would describe this random variable is called:

Accepted Answer

A) uniform distribution. 
B) Poisson distribution. 
C) continuous distribution. 
D) relative frequency distribution. 
A) uniform distribution. 
B) Poisson distribution. 
C) continuous distribution. 
D) relative frequency distribution.

The number of defects manufactured by workers in a small engine plant is an example of a discrete random variable.

If a continuous random variable is said to be exponentially distributed,what would be the easiest way to reduce the standard deviation?

For a standardized normal distribution,calculate P(1.78 < z < 2.34).

A random variable is normally distributed with a mean of 25 and a standard deviation of 5.If an observation is randomly selected from the distribution,what value will be exceeded 85% of the time?

All symmetric distributions can be assumed normally distributed.

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25.Based on this information,what is the probability that a specific fare will exceed $15.00?

For a standardized normal distribution,determine a value,say z₀,so that P(z ≤ z₀)= 0.01.

Consider a random variable,z,that has a standardized normal distribution.Determine P(z > 1.645).

For the normal distribution with parameters μ = 0,σ = 3;calculate P(x > 1).

Consider a random variable,z,that has a standardized normal distribution.Determine P(0 < z < 1.96).

For the normal distribution with parameters μ = 5,σ= 2;calculate P(0 < x < 8).

A continuous random variable approaches normality as the level of skewness increases.

It is assumed that the time customers spend in a record store is uniformly distributed between 3 and 12 minutes.Based on this information,what is the probability that a customer will spend more than 9 minutes in the record store?

A study of cars arriving at a parking structure at the local airport shows that the time between arrivals is 1.2 minutes and is exponentially distributed.Based on this information,the mean number of cars arriving per minute is about 0.83.

A store sells 6 different models of cell phones and have found that they sell an equal number of each model.The probability distribution that would describe this random variable is called:

The Where,Why,and How of Data Collection

Graphs,Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introduction to Quality and Statistical Process Control

Filters

Exam 6: Introduction to Continuous Probability Distributions

The number of defects manufactured by workers in a small engine plant is an example of a discrete random variable.

If a continuous random variable is said to be exponentially distributed,what would be the easiest way to reduce the standard deviation?

For a standardized normal distribution,calculate P(1.78 < z < 2.34).

A random variable is normally distributed with a mean of 25 and a standard deviation of 5.If an observation is randomly selected from the distribution,what value will be exceeded 85% of the time?

All symmetric distributions can be assumed normally distributed.

The fares received by taxi drivers working for the City Taxi line are normally distributed with a mean of $12.50 and a standard deviation of $3.25.Based on this information,what is the probability that a specific fare will exceed $15.00?

For a standardized normal distribution,determine a value,say z0,so that P(z ≤ z0)= 0.01.

Consider a random variable,z,that has a standardized normal distribution.Determine P(z > 1.645).

For the normal distribution with parameters μ = 0,σ = 3;calculate P(x > 1).

Consider a random variable,z,that has a standardized normal distribution.Determine P(0 < z < 1.96).

For the normal distribution with parameters μ = 5,σ= 2;calculate P(0 < x < 8).

A continuous random variable approaches normality as the level of skewness increases.

It is assumed that the time customers spend in a record store is uniformly distributed between 3 and 12 minutes.Based on this information,what is the probability that a customer will spend more than 9 minutes in the record store?

A study of cars arriving at a parking structure at the local airport shows that the time between arrivals is 1.2 minutes and is exponentially distributed.Based on this information,the mean number of cars arriving per minute is about 0.83.

A store sells 6 different models of cell phones and have found that they sell an equal number of each model.The probability distribution that would describe this random variable is called:

The Where,Why,and How of Data Collection

Graphs,Charts and Tablesdescribing Your Data

Describing Data Using Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Introduction to Sampling Distributions

Estimating Single Population Parameters

Introduction to Hypothesis Testing

Estimation and Hypothesis Testing for Two Population Parameters

Hypothesis Tests and Estimation for Population Variances

Analysis of Variance

Goodness-Of-Fit Tests and Contingency Analysis

Introduction to Linear Regression and Correlation Analysis

Multiple Regression Analysis and Model Building

Analyzing and Forecasting Time-Series Data

Introduction to Nonparametric Statistics

Introduction to Quality and Statistical Process Control

Filters

For a standardized normal distribution,determine a value,say z₀,so that P(z ≤ z₀)= 0.01.