Question 1

The significance level measures the proportion of the time an inference about a population will be correct in the long run.

Accepted Answer

The significance level, typically denoted by alpha (α), is the probability of making a Type I error, which is rejecting a null hypothesis when it is actually true. It does not measure the proportion of the time an inference about a population will be correct in the long run.

Question 2

A statistic is typically a known quantity while a parameter is typically an unknown quantity.

Accepted Answer

A statistic is a numerical value that describes a characteristic of a sample, while a parameter is a numerical value that describes a characteristic of a population. Typically, parameters are unknown and must be estimated using statistics.

Question 3

Which of the following is a measure of the reliability of a statistical inference?
A) A population parameter.
B) A significance level.
C) A descriptive statistic.
D) A sample statistic.

Accepted Answer

A significance level is the probability of rejecting a true null hypothesis. It measures the strength of evidence against the null hypothesis and helps determine the reliability of a statistical inference. The other options do not directly measure the reliability of a statistical inference.

Question 4

A descriptive measure that is computed from a sample is called a statistic.

Accepted Answer

A statistic is a descriptive measure that is computed from a sample, not the entire population.

Question 5

A descriptive measure that is computed from a sample is called a:
A) parameter.
B) statistic.
C) population.
D) sample.

Accepted Answer

Descriptive measures that are computed from a sample are called statistics. Parameters are descriptive measures that are computed from a population. Population and sample refer to the entire group or subset of individuals being analyzed.

Question 6

The process of using sample statistics to draw conclusions about population parameters is called:
A) finding the significance level.
B) calculating descriptive statistics.
C) doing inferential statistics.
D) calculating the confidence level.

Accepted Answer

Inferential statistics is the process of making generalizations or conclusions about a population based on sample data. This involves using sample statistics such as means, proportions, and variances to estimate population parameters with a certain level of confidence or probability.

Question 7

In a sample of 350 students selected from a large college of business, 25% are found to be marketing majors.The 25% is a statistic.

Accepted Answer

The statement given is a statistic as it is a numerical summary of a sample taken from a larger population.

Question 8

A random sample of 100 students is taken at LearnAll University and it's found that their average GPA is 3.1.If this information is used to help estimate the average GPA for all students at LearnAll University, which branch of statistics was applied?
A) Descriptive statistics
B) Inferential statistics
C) Sample statistics
D) Population statistics

Accepted Answer

Inferential statistics is used when making inferences about a population based on a sample. In this case, the sample of 100 students is used to estimate the average GPA for all students at LearnAll University.

Question 9

A company has developed a new computer microprocessor whose average lifetime is unknown.In order to estimate this average, 300 microprocessors are randomly selected from a large production line and tested; their average lifetime is found to be 7 years.The 300 microprocessors represent a:
A) parameter.
B) statistic.
C) sample.
D) population.

Accepted Answer

The 300 microprocessors that were chosen represent a subset of the entire production line, which makes them a sample.

Question 10

A population is the group of all items of interest to a statistics practitioner.

Accepted Answer

This is true. A population refers to the entire group of individuals or items that the statistics practitioner is interested in studying, while a sample is a smaller subset of that population used to make inferences or draw conclusions about the population.

Question 11

A company has developed a new engine whose average lifetime is unknown.In order to estimate this average, 100 engines are randomly selected from a large production line and tested; their average lifetime is found to be 11 years.The 11 years represents a:
A) parameter.
B) statistic.
C) sample.
D) population.

Accepted Answer

The 11 years represents a statistic because it is a numerical summary of a sample of 100 engines, rather than a parameter of the entire population of engines.

Question 12

A descriptive measure of a population is called a parameter.

Accepted Answer

This is a correct statement. Parameters are descriptive measures of a population, while statistics are descriptive measures of a sample.

Question 13

A descriptive measure of a sample is called a parameter.

Accepted Answer

A parameter is a descriptive measure of a population, not a sample. A descriptive measure of a sample is called a statistic.

Question 14

A councilman who is running for the office of senator of a state with 3.5 million registered voters commissions a survey.In the survey, 46% of the 8,000 registered voters interviewed say they plan to vote for him.The population of interest is:
A) the 3.5 million registered voters in the state.
B) the 8,000 registered voters interviewed.
C) the 46% who plan to vote for her.
D) all the residents of the state.

Accepted Answer

The population of interest in this scenario is the entire group of 3.5 million registered voters in the state, as this is the group that the councilman is trying to persuade to vote for him. The survey sample of only 8,000 registered voters is not representative of the entire population, and the percentage who plan to vote for him (46%) is just one data point within the larger population.

Question 15

You take a random sample to estimate a population mean and your results have a confidence level of 80%.That means the process you used will give you correct results 80% of the time.

Accepted Answer

The answer of You take a random sample to estimate...

Question 16

A company has developed a new power cell and wants to estimate its average lifetime.A random sample of 650 power cells is tested and the average lifetime of this sample is found to be 315 hours.The 315 hours is the value of a:
A) parameter.
B) statistic.
C) sample.
D) population.

Accepted Answer

The value of 315 hours is calculated from the sample of 650 power cells, making it a statistic.

Question 17

Statistical inference is the process of making an estimate, prediction, or decision about a population based on sample data.

Accepted Answer

This is the definition of statistical inference.

Question 18

A resort employs 3,500 managers and staff.To ascertain their employees' opinions of a proposed health insurance plan, 350 employees are surveyed at random.The proportion of the 350 employees who favor the health insurance plan represents a parameter in this scenario.

Accepted Answer

The proportion of the 350 employees who favor the health insurance plan represents a statistic, not a parameter, because it is a measure derived from a sample of the population, not the entire population itself.

Question 19

The confidence level is the proportion of times that an estimating procedure will be wrong in the long run.

Accepted Answer

The confidence level is actually the proportion of intervals that will contain the true population parameter in the long run. It is not the proportion of times that the estimating procedure will be wrong. Therefore, the statement is false.

Question 20

A descriptive measure that is computed from a population is called a:
A) sample.
B) statistic.
C) population.
D) parameter.

Accepted Answer

Descriptive measures that are computed from a population are called parameters. Sample statistics are computed from a subset of the population, whereas population parameters are calculated from the entire population.

Quiz 1: What Is Statistics

The significance level measures the proportion of the time an inference about a population will be correct in the long run.

A statistic is typically a known quantity while a parameter is typically an unknown quantity.

Which of the following is a measure of the reliability of a statistical inference?

A descriptive measure that is computed from a sample is called a statistic.

A descriptive measure that is computed from a sample is called a:

The process of using sample statistics to draw conclusions about population parameters is called:

In a sample of 350 students selected from a large college of business, 25% are found to be marketing majors.The 25% is a statistic.

A random sample of 100 students is taken at LearnAll University and it's found that their average GPA is 3.1.If this information is used to help estimate the average GPA for all students at LearnAll University, which branch of statistics was applied?

A company has developed a new computer microprocessor whose average lifetime is unknown.In order to estimate this average, 300 microprocessors are randomly selected from a large production line and tested; their average lifetime is found to be 7 years.The 300 microprocessors represent a:

A population is the group of all items of interest to a statistics practitioner.

A company has developed a new engine whose average lifetime is unknown.In order to estimate this average, 100 engines are randomly selected from a large production line and tested; their average lifetime is found to be 11 years.The 11 years represents a:

A descriptive measure of a population is called a parameter.

A descriptive measure of a sample is called a parameter.

A councilman who is running for the office of senator of a state with 3.5 million registered voters commissions a survey.In the survey, 46% of the 8,000 registered voters interviewed say they plan to vote for him.The population of interest is:

You take a random sample to estimate a population mean and your results have a confidence level of 80%.That means the process you used will give you correct results 80% of the time.

A company has developed a new power cell and wants to estimate its average lifetime.A random sample of 650 power cells is tested and the average lifetime of this sample is found to be 315 hours.The 315 hours is the value of a:

Statistical inference is the process of making an estimate, prediction, or decision about a population based on sample data.

A resort employs 3,500 managers and staff.To ascertain their employees' opinions of a proposed health insurance plan, 350 employees are surveyed at random.The proportion of the 350 employees who favor the health insurance plan represents a parameter in this scenario.

The confidence level is the proportion of times that an estimating procedure will be wrong in the long run.

A descriptive measure that is computed from a population is called a: