Exam 1: What Is Statistics

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)____________________.

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.

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

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

Briefly describe the difference between a parameter and a statistic, and give an example of each.

A study is under way to determine the average height of all 63,000 adult walnut trees in a certain national forest. The heights of 950 randomly selected adult walnut trees are measured and analyzed. The sample in this study is:

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:

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 descriptive measure of a population is called a parameter.

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

Which of the following represents a population, as opposed to a sample?

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

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

The significance level of a statistical inference measures:

The Human Resources Director at Illinois State University wishes to develop an employee pension package. To get an idea of what components of a pension package are most important, he selects 525 employees at random and asks them for their opinions. The group of all employees at ISU is known as the ____________________.

The Owner of a large manufacturing company wishes to develop a new employee health benefits package. He selects 500 employees at random and asks them about their preferences regarding their current health benefits package. The 500 employees selected is a(n)____________________.

How do confidence levels compare to significance levels?

The Surgeon General wanted to study malpractice litigation in Chicago. A sample of 32,000 medical records was selected from all 3.5 million patients who were discharged during the year 2011. Using the information from the sample to make conclusions about malpractice litigation in Chicago is an example of doing ____________________ statistics.

The confidence level of a statistical inference measures: