Question 1

The sampling distribution of the sample means

Accepted Answer

A)  is the probability distribution showing all possible values of the sample mean 
B)  is used as a point estimator of the population mean μ 
C)  is an unbiased estimator 
D)  shows the distribution of all possible values of μ 
A)  is the probability distribution showing all possible values of the sample mean 
B)  is used as a point estimator of the population mean μ 
C)  is an unbiased estimator 
D)  shows the distribution of all possible values of μ

Question 2

An automotive repair shop has determined that the average service time on an automobile is 2 hours with a standard deviation of 32 minutes. A random sample of 64 services is selected.
a. What is the probability that the sample of 64 will have a mean service time greater than 114 minutes?
b. Assume the population consists of 400 services. Determine the standard error of the mean.

Accepted Answer

The answer of An automotive repair shop has determined that...

Question 3

The sampling error is the

Accepted Answer

A)  same as the standard error of the mean 
B)  difference between the value of the sample mean and the value of the population mean 
C)  error caused by selecting a bad sample 
D)  standard deviation multiplied by the sample size 
A)  same as the standard error of the mean 
B)  difference between the value of the sample mean and the value of the population mean 
C)  error caused by selecting a bad sample 
D)  standard deviation multiplied by the sample size

Question 4

Random samples of size 100 are taken from an infinite population whose population proportion is 0.2. The mean and standard deviation of the sample proportion are

Accepted Answer

A)  0.2 and .04 
B)  0.2 and 0.2 
C)  20 and .04 
D)  20 and 0.2 
A)  0.2 and .04 
B)  0.2 and 0.2 
C)  20 and .04 
D)  20 and 0.2

Question 5

Students of a large university spend an average of $5 a day on lunch. The standard deviation of the expenditure is
$3. A simple random sample of 36 students is taken.
a. What are the expected value, standard deviation, and shape of the sampling distribution of the sample mean?
b. What is the probability that the sample mean will be at least $4?
c. What is the probability that the sample mean will be at least $5.90?

Accepted Answer

a. 5.0; 0.

Question 6

A department store has determined that 25% of all their sales are credit sales. A random sample of 60 sales is selected.
a. What is the sampling distribution of ?
b. What is the probability that the sample proportion will be greater than 0.30?
c. What is the probability that the sample proportion will be between 0.20 to 0.30?

Accepted Answer

a. E) = 0.25 Standar

Question 7

The number of different simple random samples of size 5 that can be selected from a population of size 8 is

Accepted Answer

A)  40 
B)  336 
C)  13 
D)  56 
A)  40 
B)  336 
C)  13 
D)  56

Question 8

A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the

Accepted Answer

A)  approximation theorem 
B)  normal probability theorem 
C)  central limit theorem 
D)  central normality theorem 
A)  approximation theorem 
B)  normal probability theorem 
C)  central limit theorem 
D)  central normality theorem

Question 9

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 standard deviation of , known as the standard error of the proportion is approximately

Accepted Answer

A)  0.5477 
B)  5.477 
C)  0.05477 
D)  54.77 
A)  0.5477 
B)  5.477 
C)  0.05477 
D)  54.77

Question 10

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. In this problem the 0.22 is

Accepted Answer

A)  a parameter 
B)  a statistic 
C)  the standard error of the mean 
D)  the average content of colognes in the long run 
A)  a parameter 
B)  a statistic 
C)  the standard error of the mean 
D)  the average content of colognes in the long run

Question 11

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 12

A single numerical value used as an estimate of a population parameter is known as

Accepted Answer

A)  a parameter 
B)  a population parameter 
C)  a mean estimator 
D)  a point estimate 
A)  a parameter 
B)  a population parameter 
C)  a mean estimator 
D)  a point estimate

Question 13

A simple random sample of 8 employees of a corporation provided the following information.
 $\begin{array} { l  }
\text { Employee }&1&2&3&4&5&6&7&8\
\text { Age }&52&32&26&40&50&54&22&23\
\text { gender }&M&M&M&M&F&M&M&F
\end{array}$
 
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

a. 34
b. 1

Question 14

A subset of a population selected to represent the population is

Accepted Answer

A)  a subset 
B)  a sample 
C)  a small population 
D)  a parameter 
A)  a subset 
B)  a sample 
C)  a small population 
D)  a parameter

Question 15

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever

Accepted Answer

A)  np ≥ 5 
B)  n1 - p) ≥ 5 and n ≥ 30 
C)  n ≥ 30 and 1 - p) = 0.5 
D)  None of these alternatives is correct. 
A)  np ≥ 5 
B)  n1 - p) ≥ 5 and n ≥ 30 
C)  n ≥ 30 and 1 - p) = 0.5 
D)  None of these alternatives is correct.

Question 16

The probability distribution of the sample mean is called the

Accepted Answer

A)  central probability distribution 
B)  sampling distribution of the mean 
C)  random variation 
D)  standard error 
A)  central probability distribution 
B)  sampling distribution of the mean 
C)  random variation 
D)  standard error

Question 17

A random sample of ten examination papers in a course that was given on a pass or fail basis showed the following scores.
 $\begin{array}{cc}\text { Paper Number }&\text { Grade }&\text { Status }\
1 & 65 & \text { Pass } \
2 & 87 & \text { Pass } \
3 & 92 & \text { Pass } \
4 & 35 & \text { Fail } \
5 & 79 & \text { Pass } \
6 & 100 & \text { Pass } \
7 & 48 & \text { Fail } \
8 & 74 & \text { Pass } \
9 & 79 & \text { Pass } \
10 & 91 & \text { Pase }
\end{array}$ 
a. What is the point estimate for the mean of the population?
b. What is the point estimate for the standard deviation of the population?
c. What is the point estimate for the proportion of all students who passed the course?

Accepted Answer

a. 75
b. 2

Question 18

Michael is running for president. The proportion of voters who favor Michael is 0.8. A simple random sample of 100 voters is taken.
a. What are the expected value, standard deviation, and shape of the sampling distribution of ?
b. What is the probability that the number of voters in the sample who will not favor Michael will be between 26 and 30?
c. What is the probability that the number of voters in the sample who will not favor Michael will be more than 16?

Accepted Answer

a. 0.8; 0.

Question 19

The following data was collected from a simple random sample of a population. 13 15 14 16 12 The point estimate of the population mean

Accepted Answer

A)  cannot be determined, since the population size is unknown 
B)  is 14 
C)  is 4 
D)  is 5 
A)  cannot be determined, since the population size is unknown 
B)  is 14 
C)  is 4 
D)  is 5

Question 20

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

The sampling distribution of the sample means

The sampling error is the

Random samples of size 100 are taken from an infinite population whose population proportion is 0.2. The mean and standard deviation of the sample proportion are

The number of different simple random samples of size 5 that can be selected from a population of size 8 is

A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the

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 standard deviation of , known as the standard error of the proportion is approximately

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. In this problem the 0.22 is

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

A single numerical value used as an estimate of a population parameter is known as

A subset of a population selected to represent the population is

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever

The probability distribution of the sample mean is called the

The following data was collected from a simple random sample of a population. 13 15 14 16 12 The point estimate of the population mean

As the sample size increases, the

Data and Statistics

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Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

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Exam 7: Sampling and Sampling Distributions

The sampling distribution of the sample means

The sampling error is the

Random samples of size 100 are taken from an infinite population whose population proportion is 0.2. The mean and standard deviation of the sample proportion are

The number of different simple random samples of size 5 that can be selected from a population of size 8 is

A theorem that allows us to use the normal probability distribution to approximate the sampling distribution of sample means and sample proportions whenever the sample size is large is known as the

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 standard deviation of , known as the standard error of the proportion is approximately

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. In this problem the 0.22 is

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

A single numerical value used as an estimate of a population parameter is known as

A subset of a population selected to represent the population is

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution whenever

The probability distribution of the sample mean is called the

The following data was collected from a simple random sample of a population. 13 15 14 16 12 The point estimate of the population mean

As the sample size increases, the

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

Comparisons Involving Means, Experimental Design, and Analysis of Variance

Comparisons Involving Proportions and a Test of Independence

Simple Linear Regression

Multiple Regression

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