Question 1

If we consider the simple random sampling process as an experiment, the sample mean is

Accepted Answer

A) always zero 
B) always smaller than the population mean 
C) a random variable 
D) exactly equal to the population mean 
A) always zero 
B) always smaller than the population mean 
C) a random variable 
D) exactly equal to the population mean

Question 2

The following information gives the number of days absent from work for a population of 5 workers at a small factory.   
a.Find the mean and the standard deviation for the population.
b.Samples of size 2 will be drawn from the population. Use the answers in part a to calculate the expected value and the standard deviation of the sampling distribution of the sample mean.
c.Find all the samples of 2 workers that can be extracted from this population. Choose the samples without replacement.
d.Compute the sample mean   for each of the samples in Part c.

Accepted Answer

a.5; 2.449
b.5; 1.5
c.AB, AC,

Question 3

The fact that the sampling distribution of sample means can be approximated by a normal probability distribution whenever the sample size is large is based on the

Accepted Answer

A) central limit theorem 
B) fact that we have tables of areas for the normal distribution 
C) assumption that the population has a normal distribution 
D) None of these alternatives is correct. 
A) central limit theorem 
B) fact that we have tables of areas for the normal distribution 
C) assumption that the population has a normal distribution 
D) None of these alternatives is correct.

Question 4

The number of random samples (without replacement) of size 3 that can be drawn from a population of size 5 is

Accepted Answer

A) 15 
B) 10 
C) 20 
D) 125 
A) 15 
B) 10 
C) 20 
D) 125

Question 5

As the sample size increases, the

Accepted Answer

A) standard deviation of the population decreases 
B) population mean increases 
C) standard error of the mean decreases 
D) standard error of the mean increases 
A) standard deviation of the population decreases 
B) population mean increases 
C) standard error of the mean decreases 
D) standard error of the mean increases

Question 6

From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximately

Accepted Answer

A) 1.1022 
B) 2 
C) 30 
D) 1.4847 
A) 1.1022 
B) 2 
C) 30 
D) 1.4847

Question 7

Four hundred people were asked whether gun laws should be more stringent. Three hundred said "yes," and 100 said "no." The point estimate of the proportion in the population who will respond "no" is

Accepted Answer

A) 75 
B) 0.25 
C) 0.75 
D) 0.50 
A) 75 
B) 0.25 
C) 0.75 
D) 0.50

Question 8

The sample mean is the point estimator of

Accepted Answer

A) $\mu$ 
B) $\sigma$ 
C)    
D)    
A) $\mu$ 
B) $\sigma$ 
C)    
D)

Question 9

Convenience sampling is an example of

Accepted Answer

A) probabilistic sampling 
B) stratified sampling 
C) nonprobabilistic sampling 
D) cluster sampling 
A) probabilistic sampling 
B) stratified sampling 
C) nonprobabilistic sampling 
D) cluster sampling

Question 10

Sampling distribution of   is the

Accepted Answer

A) probability distribution of the sample mean 
B) probability distribution of the sample proportion 
C) mean of the sample 
D) mean of the population 
A) probability distribution of the sample mean 
B) probability distribution of the sample proportion 
C) mean of the sample 
D) mean of the population

Question 11

A simple random sample of 8 employees of a corporation provided the following information.   
a.Determine the point estimate for the average age of all employees.
b.What is the point estimate for the standard deviation of the population?
c.Determine a point estimate for the proportion of all employees who are female.

Accepted Answer

The answer of A simple random sample of 8 employees...

Question 12

A finite population correction factor is needed in computing the standard deviation of the sampling distribution of sample means

Accepted Answer

A) whenever the population is infinite 
B) whenever the sample size is more than 5% of the population size 
C) whenever the sample size is less than 5% of the population size 
D) The correction factor is not necessary if the population has a normal distribution 
A) whenever the population is infinite 
B) whenever the sample size is more than 5% of the population size 
C) whenever the sample size is less than 5% of the population size 
D) The correction factor is not necessary if the population has a normal distribution

Question 13

Exhibit 7-1
A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.22 ounces.
-Refer to Exhibit 7-1. The standard error of the mean equals

Accepted Answer

A) 0.3636 
B) 0.0331 
C) 0.0200 
D) 4.000 
A) 0.3636 
B) 0.0331 
C) 0.0200 
D) 4.000

Question 14

An experimental diet to induce weight loss was followed for one week by a randomly selected group of 12 students with the following results.   
a.Find a point estimate for the average amount lost after one week on this diet. Is this an unbiased estimate of the population mean? Explain.
b.Find a point estimate for the variance of the amount lost on this diet. Is this an unbiased estimate of the population variance? Explain.
c.Find a point estimate for the standard deviation of the amount lost on this diet.

Accepted Answer

a.2.5; Yes; E( @#IMG-DLM& ) =

Question 15

Whenever the population has a normal probability distribution, the sampling distribution of   is a normal probability distribution for

Accepted Answer

A) only large sample sizes 
B) only small sample sizes 
C) any sample size 
D) only samples of size thirty or greater 
A) only large sample sizes 
B) only small sample sizes 
C) any sample size 
D) only samples of size thirty or greater

Question 16

Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the mean are

Accepted Answer

A) 200 and 18 
B) 81 and 18 
C) 9 and 2 
D) 200 and 2 
A) 200 and 18 
B) 81 and 18 
C) 9 and 2 
D) 200 and 2

Question 17

A population has a mean of 300 and a standard deviation of 18. A sample of 144 observations will be taken. The probability that the sample mean will be between 297 to 303 is

Accepted Answer

A) 0.4332 
B) 0.8664 
C) 0.9332 
D) 0.0668 
A) 0.4332 
B) 0.8664 
C) 0.9332 
D) 0.0668

Question 18

A population has a mean of 80 and a standard deviation of 7. A sample of 49 observations will be taken. The probability that the sample mean will be larger than 82 is

Accepted Answer

A) 0.5228 
B) 0.9772 
C) 0.4772 
D) 0.0228 
A) 0.5228 
B) 0.9772 
C) 0.4772 
D) 0.0228

Question 19

There are 6 children in a family. The number of children defines a population. The number of simple random samples of size 2 (without replacement) which are possible equals

Accepted Answer

A) 12 
B) 15 
C) 3 
D) 16 
A) 12 
B) 15 
C) 3 
D) 16

Question 20

Exhibit 7-3
In a local university, 40% of the students live in the dormitories. A random sample of 80 students is selected for a particular study.
-Refer to Exhibit 7-3. The probability that the sample proportion (the proportion living in the dormitories) is at least 0.30 is

Accepted Answer

A) 0.4664 
B) 0.9328 
C) 0.9664 
D) 0.0336 
A) 0.4664 
B) 0.9328 
C) 0.9664 
D) 0.0336

If we consider the simple random sampling process as an experiment, the sample mean is

The fact that the sampling distribution of sample means can be approximated by a normal probability distribution whenever the sample size is large is based on the

The number of random samples (without replacement) of size 3 that can be drawn from a population of size 5 is

As the sample size increases, the

From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximately

Four hundred people were asked whether gun laws should be more stringent. Three hundred said "yes," and 100 said "no." The point estimate of the proportion in the population who will respond "no" is

The sample mean is the point estimator of

Convenience sampling is an example of

Sampling distribution of is the

A finite population correction factor is needed in computing the standard deviation of the sampling distribution of sample means

Exhibit 7-1 A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.22 ounces. -Refer to Exhibit 7-1. The standard error of the mean equals

Whenever the population has a normal probability distribution, the sampling distribution of is a normal probability distribution for

Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the mean are

A population has a mean of 300 and a standard deviation of 18. A sample of 144 observations will be taken. The probability that the sample mean will be between 297 to 303 is

A population has a mean of 80 and a standard deviation of 7. A sample of 49 observations will be taken. The probability that the sample mean will be larger than 82 is

There are 6 children in a family. The number of children defines a population. The number of simple random samples of size 2 (without replacement) which are possible equals

Exhibit 7-3 In a local university, 40% of the students live in the dormitories. A random sample of 80 students is selected for a particular study. -Refer to Exhibit 7-3. The probability that the sample proportion (the proportion living in the dormitories) is at least 0.30 is

Data and Statistics

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Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

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Exam 7: Sampling and Sampling Distributions

If we consider the simple random sampling process as an experiment, the sample mean is

The fact that the sampling distribution of sample means can be approximated by a normal probability distribution whenever the sample size is large is based on the

The number of random samples (without replacement) of size 3 that can be drawn from a population of size 5 is

As the sample size increases, the

From a population of 500 elements, a sample of 225 elements is selected. It is known that the variance of the population is 900. The standard error of the mean is approximately

Four hundred people were asked whether gun laws should be more stringent. Three hundred said "yes," and 100 said "no." The point estimate of the proportion in the population who will respond "no" is

The sample mean is the point estimator of

Convenience sampling is an example of

Sampling distribution of is the

A finite population correction factor is needed in computing the standard deviation of the sampling distribution of sample means

Exhibit 7-1 A random sample of 121 bottles of cologne showed an average content of 4 ounces. It is known that the standard deviation of the contents (i.e., of the population) is 0.22 ounces. -Refer to Exhibit 7-1. The standard error of the mean equals

Whenever the population has a normal probability distribution, the sampling distribution of is a normal probability distribution for

Random samples of size 81 are taken from an infinite population whose mean and standard deviation are 200 and 18, respectively. The distribution of the population is unknown. The mean and the standard error of the mean are

A population has a mean of 300 and a standard deviation of 18. A sample of 144 observations will be taken. The probability that the sample mean will be between 297 to 303 is

A population has a mean of 80 and a standard deviation of 7. A sample of 49 observations will be taken. The probability that the sample mean will be larger than 82 is

There are 6 children in a family. The number of children defines a population. The number of simple random samples of size 2 (without replacement) which are possible equals

Exhibit 7-3 In a local university, 40% of the students live in the dormitories. A random sample of 80 students is selected for a particular study. -Refer to Exhibit 7-3. The probability that the sample proportion (the proportion living in the dormitories) is at least 0.30 is

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Inferences About Population Variances

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

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

Index Numbers

Decision Analysis on Website

Sample Survey on Website

Filters