Question 1

As the size of the sample is increased, the standard deviation of the sampling distribution of the sample mean for a normally distributed population will stay the same.

Accepted Answer

A) True 
 B)False

Question 2

If you randomly select a student from the first row of a business statistics class and then every other fifth student thereafter until you get a sample of 20 students, this is an example of a convenience sample.

Accepted Answer

A) True 
 B)False

Question 3

The standard error of the population proportion will become larger

Accepted Answer

A)  as population proportion approaches 0. 
B)  as population proportion approaches 0.50. 
C)  as population proportion approaches 1.00. 
D)  as the sample size increases.

Question 4

Which of the following yields a simple random sample?

Accepted Answer

A)  All students in a class are grouped according to their gender. A random sample of 8 is selected from the males and a separate random sample of 7 is drawn from the females. 
B)  The best 15 students, according to the opinion of the instructor, in a class are selected. 
C)  The names of 50 students in a class are written on 50 different pieces of paper and put in a hat. The first 15 pieces of paper are selected blindly one at a time after shuffling the papers thoroughly and each of the selected pieces is placed back into the hat before the next piece is selected. 
D)  All students in a class are divided into groups according to the rows that they are seated. One of the groups is randomly selected.

Question 5

Sampling error becomes an ethical issue if the findings are purposely presented without reference to sample size and margin of error so that the sponsor can promote a viewpoint that might otherwise be truly insignificant.

Accepted Answer

A) True 
 B)False

Question 6

TABLE 7-3
The mean selling price of new homes in a small town over a year was $115,000. The population standard deviation was $25,000. A random sample of 100 new home sales from this city was taken.
-Referring to Table 7-3, what is the probability that the sample mean selling price was between $113,000 and $117,000?

Accepted Answer

The answer of TABLE 7-3
The mean selling price of new...

Question 7

TABLE 7-5
According to a survey, only 15% of customers who visited the website of a major retail store made a purchase. Random samples of size 50 are selected.
-Referring to Table 7-5, what proportion of the samples will have between 20% and 30% of customers who will make a purchase after visiting the website?

Accepted Answer

The answer of TABLE 7-5
According to a survey, only 15%...

Question 8

Which of the following sampling methods will more likely be susceptible to ethical violation?

Accepted Answer

A)  Simple random sample 
B)  Cluster sample 
C)  Convenience sample 
D)  Stratified sample

Question 9

For sample size 16, the sampling distribution of the mean will be approximately normally distributed

Accepted Answer

A)  regardless of the shape of the population. 
B)  if the shape of the population is symmetrical. 
C)  if the sample standard deviation is known. 
D)  if the sample is normally distributed.

Question 10

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The probability that the mean of the sample is between 35.95 and 35.98 oz. is ________.

Accepted Answer

The answer of The amount of bleach a machine pours...

Question 11

The amount of tea leaves in a can from a particular production line is normally distributed with μ = 110 grams and σ = 25 grams. A sample of 25 cans is to be selected. So, 95% of all sample means will be greater than how many grams?

Accepted Answer

The answer of The amount of tea leaves in a...

Question 12

TABLE 7-5
According to a survey, only 15% of customers who visited the website of a major retail store made a purchase. Random samples of size 50 are selected.
-A study at a college in the west coast reveals that, historically, 45% of the students are minority students. If random samples of size 75 are selected, 80% of the samples will have less than ________ % of minority students.

Accepted Answer

The answer of TABLE 7-5
According to a survey, only 15%...

Question 13

The sample mean is an unbiased estimate of the population mean.

Accepted Answer

A) True 
 B)False

Question 14

The Central Limit Theorem is important in statistics because

Accepted Answer

A)  for a large n, it says the population is approximately normal. 
B)  for any population, it says the sampling distribution of the sample mean is approximately normal, regardless of the sample size. 
C)  for a large n, it says the sampling distribution of the sample mean is approximately normal, regardless of the shape of the population. 
D)  for any sized sample, it says the sampling distribution of the sample mean is approximately normal.

Question 15

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The probability that the mean of the sample exceeds 36.01 oz. is ________.

Accepted Answer

The answer of The amount of bleach a machine pours...

Question 16

A convenience sample is a type of probability sample.

Accepted Answer

A) True 
 B)False

Question 17

The amount of time required for an oil and filter change on an automobile is normally distributed with a mean of 45 minutes and a standard deviation of 10 minutes. A random sample of 16 cars is selected. 90% of the sample means will be greater than what value?

Accepted Answer

The answer of The amount of time required for an...

Exam 7: Sampling and Sampling Distributions

As the size of the sample is increased, the standard deviation of the sampling distribution of the sample mean for a normally distributed population will stay the same.

If you randomly select a student from the first row of a business statistics class and then every other fifth student thereafter until you get a sample of 20 students, this is an example of a convenience sample.

The standard error of the population proportion will become larger

Which of the following yields a simple random sample?

Sampling error becomes an ethical issue if the findings are purposely presented without reference to sample size and margin of error so that the sponsor can promote a viewpoint that might otherwise be truly insignificant.

Which of the following sampling methods will more likely be susceptible to ethical violation?

For sample size 16, the sampling distribution of the mean will be approximately normally distributed

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The probability that the mean of the sample is between 35.95 and 35.98 oz. is ________.

The amount of tea leaves in a can from a particular production line is normally distributed with μ = 110 grams and σ = 25 grams. A sample of 25 cans is to be selected. So, 95% of all sample means will be greater than how many grams?

The sample mean is an unbiased estimate of the population mean.

The Central Limit Theorem is important in statistics because

The amount of bleach a machine pours into bottles has a mean of 36 oz. with a standard deviation of 0.15 oz. Suppose we take a random sample of 36 bottles filled by this machine. The probability that the mean of the sample exceeds 36.01 oz. is ________.

A convenience sample is a type of probability sample.

The amount of time required for an oil and filter change on an automobile is normally distributed with a mean of 45 minutes and a standard deviation of 10 minutes. A random sample of 16 cars is selected. 90% of the sample means will be greater than what value?