Exam 1: What Is Statistics

A manufacturer of microwave ovens wants to know what percentage of all of their microwave ovens are defective.When 450 of their microwave ovens are selected at random and examined,0.4% are found to be defective. a.Describe the population of interest. b.Describe the sample. c.Describe/find the parameter. d.Describe/find the statistic. e.Is the 0.4% a parameter or a statistic in this scenario? Why?

The Human Resources Director of a large hospital wants to determine the percentage of all employees who favor a newly proposed benefits package.He selects 300 employees at random and finds that 85% approve the newly proposed package.The percentage of all employees of this company who favor the newly proposed package is a(n)____________________.

​One source of data used in thisChapter is the SCF.What does this acronym mean?

The Commissioner of Health in the state of New York wanted to study malpractice litigation in Albany last year.She randomly selected 53,000 medical records from the population of 2.5 million patients in Albany last year.The proportion of malpractice claims filed from the 53,000 patients is an example of a(n)____________________.

What name do we give to a descriptive measure of a sample?

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:

Briefly describe the difference between a population and a sample and give an example of each.

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:

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.

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

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.

A descriptive measure of a population is called a parameter.

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

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

35% of a sample of 300 professional baseball players indicated that their parents did not play baseball.Based on this sample,we estimate that approximately 35% of the parents of all professional baseball players did not play baseball,plus or minus 5%.This is an example of using inferential statistics.

What name do we give to a descriptive measure of a population?

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:

Each of the following is a form of doing ____________________ statistics: 1)presenting your data using a graph; 2)calculating the mean of your sample; and 3)organizing your data into a table.

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

Identify each of the following as a use of descriptive statistics or inferential statistics. a.Finding the weights of a sample of 85 manufacturer parts. b.Calculating the average weight of 125 boxes shipped by FedEx. c.Estimating the percentage of the U.S.population that will vote for your favorite candidate in the next presidential election. d.Selecting a random sample of 190 babies born last year and using this information to estimate the birth weight of all babies born last year. e.Randomly selecting 225 cans of a brand of peas and using their average weight to decide whether the 15 oz.label on the cans is truthful or not.