Question 1

Using the central limit theorem, applied to the sampling distribution of the sample proportion, what conditions must be met?

Accepted Answer

A)  np ≥ 5 and n(1 - p) ≤ 5 
B)  np ≤ 5 and n(1 - p) ≥ 5 
C)  np ≥ 5 and n(1 - p) ≥ 5 
D)  np ≤ 5 and n(1 - p) ≤ 5 
A)  np ≥ 5 and n(1 - p) ≤ 5 
B)  np ≤ 5 and n(1 - p) ≥ 5 
C)  np ≥ 5 and n(1 - p) ≥ 5 
D)  np ≤ 5 and n(1 - p) ≤ 5

Question 2

In any production process, variations in the quality of the end product are inevitable. Assignable variation refers to ________.

Accepted Answer

A)  the variation caused by stratified random sampling 
B)  the variation caused by the use of the finite correction factor 
C)  specific events or factors that can usually be identified and eliminated 
D)  a number of randomly occurring events that are part of the production process 
A)  the variation caused by stratified random sampling 
B)  the variation caused by the use of the finite correction factor 
C)  specific events or factors that can usually be identified and eliminated 
D)  a number of randomly occurring events that are part of the production process

Question 3

A point estimator refers to an estimator that provides a single value.

Accepted Answer

A) True 
 B)False

Question 4

Over the entire six years that students attend an Ohio elementary school, they are absent, on average, 28 days due to influenza. Assume that the standard deviation over this time period is σ = 9 days. Upon graduation from elementary school, a random sample of 36 students is taken and asked how many days of school they missed due to influenza. The probability that the sample mean is less than 30 school days is ________.

Accepted Answer

A)  0.0918 
B)  0.4129 
C)  0.5871 
D)  0.9088 
A)  0.0918 
B)  0.4129 
C)  0.5871 
D)  0.9088

Question 5

A random sample of size 100 is taken from a population described by the proportion p = 0.60. The probability that the sample proportion is less than 0.55 is ________.

Accepted Answer

A)  ≈0 
B)  0.1537 
C)  0.3669 
D)  0.8461 
A)  ≈0 
B)  0.1537 
C)  0.3669 
D)  0.8461

Question 6

According to the central limit theorem, the distribution of the sample means is normal if ________.

Accepted Answer

A)  the underlying population is normal 
B)  the sample size n ≥ 30 
C)  the standard deviation of the population is known 
D)  both the underlying population is normal and the sample size n ≥ 30 are correct 
A)  the underlying population is normal 
B)  the sample size n ≥ 30 
C)  the standard deviation of the population is known 
D)  both the underlying population is normal and the sample size n ≥ 30 are correct

Question 7

We are told that 8% of college graduates, under the age of 25 are unemployed. What is the probability that at least 200 out of 215 college graduates under age 25 are employed?

Accepted Answer

A)  0.8925 
B)  0.7088 
C)  0.2901 
D)  0.1075 
A)  0.8925 
B)  0.7088 
C)  0.2901 
D)  0.1075

Question 8

Which of the following is considered an estimate?

Accepted Answer

A)  μ = 12 
B)    = 20 
C)  σ = 3.2 
D)  σ2 = 10 
A)  μ = 12 
B)    = 20 
C)  σ = 3.2 
D)  σ2 = 10

Question 9

In a recent investigation, the National Highway Traffic Safety Administration (NHTSA) found that the Chevrolet Volt and other electric vehicles do not pose a greater risk of fire than gasoline-powered vehicles (The Boston Globe, January 25, 2012). Specifically, it was determined that "no discernible defect trend exists." Suppose a consumer advocacy group wants to verify some of these claims by constructing a   chart. The group expects 2% of electric cars to catch fire each month. For each of the last six months, 500 electric car owners are asked if their cars have caught fire. These sample proportions are obtained:
0.010 0.020 0.015 0.030 0.025 0.015.
A) Assuming that the group expectation is correct, construct the centerline and the upper and lower control limits for the   chart.
B) Do the consumer group's findings support those of the NHTSA? Explain the answer.

Accepted Answer

a. UCL =0.02+3*SQRT(0.02*(1-0.02)/500) =

Question 10

Suppose the average casino patron in Las Vegas loses $110 per day, with a standard deviation of $700. Assume winnings/losses are normally distributed.
A) What is the probability that a random group of nine people averages more than $500 in winnings on their one-day trip to Las Vegas?
B) What is the probability that a random group of nine people averages more than $500 in losses on their one-day trip to Las Vegas?

Accepted Answer

The answer of Suppose the average casino patron in Las...

Question 11

If a population is known to be normally distributed, what can be said of the sampling distribution of the sample mean drawn from this population?

Accepted Answer

A)  For any sample size n, the sampling distribution of the sample mean is normally distributed. 
B)  For a sample size n  30, the sampling distribution of the sample mean is normally distributed. 
A)  For any sample size n, the sampling distribution of the sample mean is normally distributed. 
B)  For a sample size n  30, the sampling distribution of the sample mean is normally distributed.

Question 12

A mining company made some changes to their mining process in an attempt to save fuel. Before the changes were made, it took an average of 20 gallons of diesel fuel to mine 1,000 pounds of copper. Suppose the standard deviation of fuel used per 1,000 pounds of copper mined is 6 gallons. After the changes were made, the company only used an average of 18 gallons of diesel for the next 30,000 pounds of copper mined.
A) How unusual would it be to get a sample average of 18 gallons or less for 30,000 pounds of copper mined if the changes to the mining process had no effect?
B) Do you think the changes in the mining process actually lowered the fuel used? Explain.

Accepted Answer

a. 0.03394
b. Yes, it's very u

Question 13

What is the relationship between the expected value of the sample mean and the expected value of the population?

Accepted Answer

A)  E(   ) = E(X) = μ 
B)  E(   ) = E(X) =   
C)  E(   ) = E(X) =   
D)  E(   ) = E(X) =   
A)  E(   ) = E(X) = μ 
B)  E(   ) = E(X) =   
C)  E(   ) = E(X) =   
D)  E(   ) = E(X) =

Question 14

Over the entire six years that students attend an Ohio elementary school, they are absent, on average, 28 days due to influenza. Assume that the standard deviation over this time period is σ = 9 days. Upon graduation from elementary school, a random sample of 36 students is taken and asked how many days of school they missed due to influenza. What is the standard deviation for the sampling distribution of the number of school days missed due to influenza?

Accepted Answer

A)  1.22 
B)  1.50 
C)  2.25 
D)  9.00 
A)  1.22 
B)  1.50 
C)  2.25 
D)  9.00

Question 15

A random sample of size 100 is taken from a population described by the proportion p = 0.60. The probability that the sample proportion is greater than 0.62 is ________.

Accepted Answer

A)  0.3415 
B)  0.4082 
C)  0.6591 
D)  ≈1 
A)  0.3415 
B)  0.4082 
C)  0.6591 
D)  ≈1

Question 16

A parameter is a random variable, whereas a sample statistic is a constant.

Accepted Answer

A) True 
 B)False

Question 17

Suppose residents in a well-to-do neighborhood pay an average overall tax rate of 25% with a standard deviation of 8%. Assume tax rates are normally distributed. What is the probability that the mean tax rate of 16 randomly selected residents is between 20% and 30%.

Accepted Answer

The answer of Suppose residents in a well-to-do neighborhood pay...

Question 18

For qualitative data, the most appropriate control chart to monitor the proportion of a certain characteristic is a(n)

Accepted Answer

A)    chart. 
B)    chart. 
C)  c chart. 
D)  s chart. 
A)    chart. 
B)    chart. 
C)  c chart. 
D)  s chart.

Question 19

According to the 2011 Gallup daily tracking polls (www.gallup.com, February 3, 2012), Mississippi is the most conservative U.S. state, with 53.4 percent of its residents identifying themselves as conservative. What is the probability that at least 50 respondents of a random sample of 100 Mississippi residents do not identify themselves as conservative?

Accepted Answer

A)  0.0499 
B)  0.2478 
C)  0.4966 
D)  0.7517 
A)  0.0499 
B)  0.2478 
C)  0.4966 
D)  0.7517

Question 20

Selection bias occurs when the sample is mistakenly divided into strata, and random samples are drawn from each stratum.

Accepted Answer

A) True 
 B)False

Using the central limit theorem, applied to the sampling distribution of the sample proportion, what conditions must be met?

In any production process, variations in the quality of the end product are inevitable. Assignable variation refers to ________.

A point estimator refers to an estimator that provides a single value.

A random sample of size 100 is taken from a population described by the proportion p = 0.60. The probability that the sample proportion is less than 0.55 is ________.

According to the central limit theorem, the distribution of the sample means is normal if ________.

We are told that 8% of college graduates, under the age of 25 are unemployed. What is the probability that at least 200 out of 215 college graduates under age 25 are employed?

Which of the following is considered an estimate?

If a population is known to be normally distributed, what can be said of the sampling distribution of the sample mean drawn from this population?

What is the relationship between the expected value of the sample mean and the expected value of the population?

A random sample of size 100 is taken from a population described by the proportion p = 0.60. The probability that the sample proportion is greater than 0.62 is ________.

A parameter is a random variable, whereas a sample statistic is a constant.

Suppose residents in a well-to-do neighborhood pay an average overall tax rate of 25% with a standard deviation of 8%. Assume tax rates are normally distributed. What is the probability that the mean tax rate of 16 randomly selected residents is between 20% and 30%.

For qualitative data, the most appropriate control chart to monitor the proportion of a certain characteristic is a(n)

Selection bias occurs when the sample is mistakenly divided into strata, and random samples are drawn from each stratum.

Statistics and Data

Tabular and Graphical Methods

Numerical Descriptive Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability 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 7: Sampling and Sampling Distributions

Using the central limit theorem, applied to the sampling distribution of the sample proportion, what conditions must be met?

In any production process, variations in the quality of the end product are inevitable. Assignable variation refers to ________.

A point estimator refers to an estimator that provides a single value.

A random sample of size 100 is taken from a population described by the proportion p = 0.60. The probability that the sample proportion is less than 0.55 is ________.

According to the central limit theorem, the distribution of the sample means is normal if ________.

We are told that 8% of college graduates, under the age of 25 are unemployed. What is the probability that at least 200 out of 215 college graduates under age 25 are employed?

Which of the following is considered an estimate?

If a population is known to be normally distributed, what can be said of the sampling distribution of the sample mean drawn from this population?

What is the relationship between the expected value of the sample mean and the expected value of the population?

A random sample of size 100 is taken from a population described by the proportion p = 0.60. The probability that the sample proportion is greater than 0.62 is ________.

A parameter is a random variable, whereas a sample statistic is a constant.

Suppose residents in a well-to-do neighborhood pay an average overall tax rate of 25% with a standard deviation of 8%. Assume tax rates are normally distributed. What is the probability that the mean tax rate of 16 randomly selected residents is between 20% and 30%.

For qualitative data, the most appropriate control chart to monitor the proportion of a certain characteristic is a(n)

Selection bias occurs when the sample is mistakenly divided into strata, and random samples are drawn from each stratum.

Statistics and Data

Tabular and Graphical Methods

Numerical Descriptive Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability 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