Question 1

A university has 5,000 students. The manager of food services at the university is interested in determining the total lunch expenditure. A simple random sample of 121 lunch receipts was selected. The sample showed an average of $3 with a standard deviation of $0.40.
a.Estimate the standard error of the sample mean.
b.Develop an approximate 95% confidence interval for the population mean.
c.Estimate the population's total expenditure for lunch.
d.Develop an approximate 95% confidence interval for the total expenditure for lunch.

Accepted Answer

The answer of A university has 5,000 students. The manager...

Question 2

We are interested in selecting a sample from a population of size 4,000 in order to develop an approximate 95% confidence interval estimate of the population mean. A pilot study has resulted in a standard deviation of 600. What should be the sample size if we do not want the sampling error to exceed 200?

Accepted Answer

The answer of We are interested in selecting a sample...

Question 3

Exhibit 21-4
Simple random sampling has been used to obtain a sample of size 50 from a population of size 500. The sample proportion was 0.7.
-Refer to Exhibit 21-4. An approximate 95% confidence interval for the population proportion is
A)0.500 to 0.700
B)0.750 to 0.810
C)0.576 to 0.824
D)0.638 to 0.762

Accepted Answer

The formula for the confidence interval for a proportion is:
sample proportion +/- z* (standard error)
where z* is the critical value from the standard normal distribution for the desired level of confidence (in this case, 95%).

The standard error of the proportion is:
sqrt[(sample proportion * (1 - sample proportion)) / sample size]

Plugging in the values we have:
sample proportion = 0.7
sample size = 50
z* for 95% confidence is approximately 1.96 (from the standard normal table)

standard error = sqrt[(0.7 * 0.3) / 50] = 0.084

Confidence interval = 0.7 +/- 1.96*(0.084) = 0.576 to 0.824

So the best choice is C.

Question 4

A simple random sample of size 36 is selected from a population of size 750. The sample mean is 318, and the sample standard deviation is found to be 30.
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean.

Accepted Answer

The answer of A simple random sample of size 36...

Question 5

A company has 600 employees. A random sample of 49 employees took a computer literacy test. The sample resulted in a mean score of 75 with a standard deviation of 21.
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean of the 600 employees.

Accepted Answer

The answer of A company has 600 employees. A random...

Question 6

From a population of 2000 accounts receivable, a simple random sample of 120 accounts is selected. Thirty-six of the accounts in the sample were overdue.
a.Estimate the standard error of the proportion of the overdue accounts.
b.Develop an approximate 95% confidence interval for the proportion of overdue accounts in the population.

Accepted Answer

The answer of From a population of 2000 accounts receivable,...

Question 7

Simple random sampling has been used to obtain a sample of size 60 from a population of size 700. The sample mean was 500 with a standard deviation of 60.
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean.

Accepted Answer

The answer of Simple random sampling has been used to...

Question 8

Simple random sampling has been used to obtain a sample of n = 40 elements from a population of N=300. The sample proportion  
a.Estimate the standard error of the proportion.
b.Develop an approximate 95% confidence interval for the population proportion.

Accepted Answer

The answer of Simple random sampling has been used to...

Question 9

Nancy Joon, Inc. has 1500 employees. A simple random sample of 81 employees was selected, and the individuals in the sample were asked how much they contribute (monthly) to their retirement accounts. The sample mean,  , was $150 with a standard deviation, s, of $45. 
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean.

Accepted Answer

The answer of Nancy Joon, Inc. has 1500 employees. A...

Question 10

Not sampling from the intended target population is an example of
A)stratified sampling
B)sampling error
C)cluster sampling
D)nonsampling error

Accepted Answer

Sampling error occurs when the sample is not representative of the target population. This mistake can be caused by a variety of factors, such as selecting a biased sample or having a low response rate.

Question 11

A list of the sampling units for a study is called a
A)frame
B)cluster
C)stratum
D)population

Accepted Answer

A list of the sampling units for a study is typically referred to as a frame. Clusters and strata are subsets of the population, while the population is the entire group being studied, so they are not the best choice.

Question 12

Simple random sampling has been used to obtain a sample of 81 elements from a population of size 500. The sample mean is 120, and the sample standard deviation is determined to be 36.
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean.
c.Estimate the population total.
d.Develop an approximate 95% confidence interval for the population total.

Accepted Answer

The answer of Simple random sampling has been used to...

Question 13

A random sample of 60 elements was selected from a population of size 400. The sample proportion  
a.Estimate the standard error of the proportion.
b.Develop an approximate 95% confidence interval for the population proportion.

Accepted Answer

The answer of A random sample of 60 elements was...

Question 14

Assume simple random sampling has been used, and the following information was obtained.  
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean.

Accepted Answer

The answer of Assume simple random sampling has been used,...

Question 15

A community has 2,000 registered voters. A pilot study revealed that 70% of the individuals are planning to vote for the incumbent mayor. We are interested in selecting a sample. So that the sampling error will not exceed 4%, what size sample should be taken?

Accepted Answer

The answer of A community has 2,000 registered voters. A...

Question 16

Selecting a subset of clusters and then selecting a sample of elements in each of those clusters is referred to as
A)stratified cluster sampling
B)convenient cluster sampling
C)single-stage cluster sampling
D)two-stage cluster sampling

Accepted Answer

Selecting a subset of clusters and then selecting a sample of elements in each of those clusters is a two-stage cluster sampling. This is because it involves sampling from within selected clusters, which constitutes the second stage of sampling. Therefore, D (two-stage cluster sampling) is the correct answer. A (stratified cluster sampling) refers to dividing the population into strata and then selecting clusters from each stratum, while B (convenient cluster sampling) is not a recognized sampling method. C (single-stage cluster sampling) involves selecting all elements in selected clusters, without using a subset of the clusters.

Question 17

The accounting firm of Nancy Amari & Associates (NAA) was commissioned to audit a population of 500 accounts. For this audit, NAA selected a simple random sample of 64 accounts. The sample showed an average discrepancy of $120 with a standard deviation of $24.
a.Estimate the population total discrepancy.
b.Develop an approximate 95% confidence interval for the population total discrepancy.

Accepted Answer

The answer of The accounting firm of Nancy Amari &...

Question 18

Selecting a subset of clusters and then collecting data on all elements in those clusters is referred to as
A)stratified cluster sampling
B)convenient cluster sampling
C)single-stage cluster sampling
D)two-stage cluster sampling

Accepted Answer

In single-stage cluster sampling, entire clusters are selected, and data is collected from all elements within those clusters.

Question 19

Survey costs are highest for
A)mail surveys
B)personal interview surveys
C)Internet surveys
D)telephone surveys

Accepted Answer

Personal interview surveys typically require trained interviewers to travel to various locations to conduct interviews with respondents. This incurs travel and salary expenses, making it the most expensive survey method.

Question 20

From a population consisting of 8,000 elements, a sample of size 121 is selected. The sample has a mean of 4,000 and a standard deviation of 600.
a.Estimate the standard error of the mean.
b.Develop an approximate 95% confidence interval for the population mean.
c.Estimate the population total.
d.Develop an approximate 95% confidence interval for the population total.

Accepted Answer

The answer of From a population consisting of 8,000 elements,...

Quiz 21: Sample Survey

Exhibit 21-4 Simple random sampling has been used to obtain a sample of size 50 from a population of size 500. The sample proportion was 0.7. -Refer to Exhibit 21-4. An approximate 95% confidence interval for the population proportion is

A simple random sample of size 36 is selected from a population of size 750. The sample mean is 318, and the sample standard deviation is found to be 30. a.Estimate the standard error of the mean. b.Develop an approximate 95% confidence interval for the population mean.

Simple random sampling has been used to obtain a sample of size 60 from a population of size 700. The sample mean was 500 with a standard deviation of 60. a.Estimate the standard error of the mean. b.Develop an approximate 95% confidence interval for the population mean.

Simple random sampling has been used to obtain a sample of n = 40 elements from a population of N=300. The sample proportion a.Estimate the standard error of the proportion. b.Develop an approximate 95% confidence interval for the population proportion.

Not sampling from the intended target population is an example of

A list of the sampling units for a study is called a

A random sample of 60 elements was selected from a population of size 400. The sample proportion a.Estimate the standard error of the proportion. b.Develop an approximate 95% confidence interval for the population proportion.

Assume simple random sampling has been used, and the following information was obtained. a.Estimate the standard error of the mean. b.Develop an approximate 95% confidence interval for the population mean.

A community has 2,000 registered voters. A pilot study revealed that 70% of the individuals are planning to vote for the incumbent mayor. We are interested in selecting a sample. So that the sampling error will not exceed 4%, what size sample should be taken?

Selecting a subset of clusters and then selecting a sample of elements in each of those clusters is referred to as

Selecting a subset of clusters and then collecting data on all elements in those clusters is referred to as

Survey costs are highest for