Question 1

Find the z value such that   .

Accepted Answer

A) z = -1.33 
B) z = 0.1814 
C) z = 0.8186 
D) z = 1.33 
A) z = -1.33 
B) z = 0.1814 
C) z = 0.8186 
D) z = 1.33

Question 2

Suppose the amount of time customers must wait to check bags at the ticketing counter in Boston Logan Airport is exponentially distributed with a mean of 14 minutes.What is the probability that a randomly selected customer will have to wait more than 20 minutes?

Accepted Answer

The answer of Suppose the amount of time customers must...

Question 3

The probability P(Z > 1.28)is closest to ____.

Accepted Answer

A) -0.10 
B) 0.10 
C) 0.20 
D) 0.90 
A) -0.10 
B) 0.10 
C) 0.20 
D) 0.90

Question 4

Exhibit 6-2.Gold miners in Alaska have found,on average,12 ounces of gold per 1000 tons of dirt excavated with a standard deviation of 3 ounces.Assume the amount of gold found per 1000 tons of dirt is normally distributed. Refer to Exhibit 6-2.What is the probability the miners find between 10 and 14 ounces of gold in the next 1000 tons of dirt excavated?

Accepted Answer

A) 0.2514 
B) 0.4972 
C) 0.5028 
D) 0.7486 
A) 0.2514 
B) 0.4972 
C) 0.5028 
D) 0.7486

Question 5

If an exponential distribution has the rate parameter λ = 5,what is its variance?

Accepted Answer

A) 5 
B) 1/5 
C) 1/25 
D) 5/2 
A) 5 
B) 1/5 
C) 1/25 
D) 5/2

Question 6

The probability density function of a normal distribution is in general characterized by being symmetric and bell-shaped.

Accepted Answer

A) True 
 B)False

Question 7

Snack food companies always have a target weight when filling a box of snack crackers.It is not possible,however,to always fill boxes to the exact target weight.For a particular box of crackers,the target weight is 14 ounces.The filling machine drops between 13.5 and 15 ounces of crackers into each box.If these weights are uniformly distributed,what is the expected value of the fill weights? Does this value match the target weight? If not,what impact does this difference have on the manufacturer's costs to produce these crackers?

Accepted Answer

The expected value equals 14.2

Question 8

Which of the following does not represent a continuous random variable?

Accepted Answer

A) Height of oak trees in a park. 
B) Heights and weights of newborn babies. 
C) Time of a flight between Chicago and New York. 
D) The number of customer arrivals to a bank between 10 am and 11 am. 
A) Height of oak trees in a park. 
B) Heights and weights of newborn babies. 
C) Time of a flight between Chicago and New York. 
D) The number of customer arrivals to a bank between 10 am and 11 am.

Question 9

Snack food companies always have a target weight when filling a box of snack crackers.It is not possible,however,to always fill boxes to the exact target weight.For a particular box of crackers,the target weight is 14 ounces.The filling machine drops between 13.5 and 15 ounces of crackers into each box.Let these weights be uniformly distributed.
A)What is the probability that the weight in a box will be less than 14 ounces?
B)What is the probability that the weight in a box will be between 14.5 and 15.5 ounces?

Accepted Answer

The answer of Snack food companies always have a target...

Question 10

Alex is in a hurry to get to work and is rushing to catch the bus.She knows that the bus arrives every six minutes during rush hour,but does not know the exact times the bus is due.She realizes that from the time she arrives at the stop,the amount of time that she will have to wait follows a uniform distribution with a lower bound of 0 minutes and an upper bound of six minutes.What is the probability that she will have to wait more than two minutes?

Accepted Answer

A) 0.1667 
B) 0.3333 
C) 0.6667 
D) 1.0000 
A) 0.1667 
B) 0.3333 
C) 0.6667 
D) 1.0000

Question 11

The time to complete the construction of a soapbox derby car is normally distributed with a mean of three hours and a standard deviation of one hour.Find the probability that it would take more than five hours to construct a soapbox derby car.

Accepted Answer

A) 0 
B) 0.0228 
C) 0.4772 
D) 0.9772 
A) 0 
B) 0.0228 
C) 0.4772 
D) 0.9772

Question 12

The annual return of a well-known mutual fund has historically had a mean of about 10% and a standard deviation of 21%.Suppose the return for the following year follows a normal distribution,with the historical mean and standard deviation.What is the probability that you will lose money in the next year by investing in this fund?

Accepted Answer

The answer of The annual return of a well-known mutual...

Question 13

Find the probability P(-1.96 ≤ Z ≤ 0).

Accepted Answer

A) 0.0250 
B) 0.0500 
C) 0.4750 
D) 0.5250 
A) 0.0250 
B) 0.0500 
C) 0.4750 
D) 0.5250

Question 14

Which of the following is correct?

Accepted Answer

A) A continuous random variable has a probability density function but not a cumulative distribution function. 
B) A discrete random variable has a probability mass function but not a cumulative distribution function. 
C) A continuous random variable has a probability mass function,and a discrete random variable has a probability density function. 
D) A continuous random variable has a probability density function,and a discrete random variable has a probability mass function. 
A) A continuous random variable has a probability density function but not a cumulative distribution function. 
B) A discrete random variable has a probability mass function but not a cumulative distribution function. 
C) A continuous random variable has a probability mass function,and a discrete random variable has a probability density function. 
D) A continuous random variable has a probability density function,and a discrete random variable has a probability mass function.

Find the z value such that .

Suppose the amount of time customers must wait to check bags at the ticketing counter in Boston Logan Airport is exponentially distributed with a mean of 14 minutes.What is the probability that a randomly selected customer will have to wait more than 20 minutes?

The probability P(Z > 1.28)is closest to ____.

If an exponential distribution has the rate parameter λ = 5,what is its variance?

The probability density function of a normal distribution is in general characterized by being symmetric and bell-shaped.

Which of the following does not represent a continuous random variable?

The time to complete the construction of a soapbox derby car is normally distributed with a mean of three hours and a standard deviation of one hour.Find the probability that it would take more than five hours to construct a soapbox derby car.

Find the probability P(-1.96 ≤ Z ≤ 0).

Which of the following is correct?

Statistics and Data

Tabular and Graphical Methods

Numerical Descriptive Measures

Basic Probability Concepts

Discrete Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Testing

Statistical Inference Concerning Two Populations

Statistical Inference Concerning Variance

Chi-Square Tests

Analysis of Variance

Regression Analysis

Inference With Regression Models

Regression Models for Nonlinear Relationships

Regression Models With Dummy Variables

Time Series and Forecasting

Returns, Index Numbers and Inflation

Nonparametric Tests

Filters

Exam 6: Continuous Probability Distributions

Find the z value such that .

Suppose the amount of time customers must wait to check bags at the ticketing counter in Boston Logan Airport is exponentially distributed with a mean of 14 minutes.What is the probability that a randomly selected customer will have to wait more than 20 minutes?

The probability P(Z > 1.28)is closest to ____.

If an exponential distribution has the rate parameter λ = 5,what is its variance?

The probability density function of a normal distribution is in general characterized by being symmetric and bell-shaped.

Which of the following does not represent a continuous random variable?

The time to complete the construction of a soapbox derby car is normally distributed with a mean of three hours and a standard deviation of one hour.Find the probability that it would take more than five hours to construct a soapbox derby car.

Find the probability P(-1.96 ≤ Z ≤ 0).

Which of the following is correct?

Statistics and Data

Tabular and Graphical Methods

Numerical Descriptive Measures

Basic Probability Concepts

Discrete Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Testing

Statistical Inference Concerning Two Populations

Statistical Inference Concerning Variance

Chi-Square Tests

Analysis of Variance

Regression Analysis

Inference With Regression Models

Regression Models for Nonlinear Relationships

Regression Models With Dummy Variables

Time Series and Forecasting

Returns, Index Numbers and Inflation

Nonparametric Tests

Filters