INTRO TO STAT

The average age of the students in a statistics class is 22 years. Does this statement describe descriptive or inferential statistics?

• Inferential statistics       

• Descriptive statistics

From past figures, it is predicted that 30% of the registered voters will vote in the March primary. Does this statement describe descriptive or inferential statistics?

• Descriptive statistics      

• Inferential statistics

The process of using information from a sample to make generalizations about the larger population is called statistical inference.

•  True

• False

Which of the following is not an element of descriptive statistical problems?

• information revealed in a data set is summarized

• predictions are made about a larger set of data

• data are displayed visually in graphs

• patterns in a data set are identified

An assembly line is operating satisfactorily if fewer than 4% of the phones produced per day are defective. To check the quality of a day's production, the company randomly samples 10 phones from a day's production to test for defects. Define the population of interest to the manufacturer.

• the 10 phones sampled and tested

• all the phones produced during the day in question

• the 4% of the phones that are defective

• the 10 responses: defective or not defective

An insurance company conducted a study to determine the percentage of cardiologists who had been sued for malpractice in the previous three years. The sample was randomly chosen from a national directory of doctors. What is the variable of interest in this study?

• the doctor's area of expertise (i.e., cardiology, pediatrics, etc.)

• the responses: have been sued/have not been sued for malpractice in the last three years

• all cardiologists in the directory

•  the number of doctors who are cardiologists

A postal worker counts the number of complaint letters received by the United States Postal Service in a given day. Identify the type of data collected

• qualitative

• quantitative

An usher records the number of unoccupied seats in a movie theater during each viewing of a film. Identify the type of data collected

• qualitative

• quantitative

A fan observes the numbers on the shirts of a girl's soccer team. Identify the type of data collected.

• qualitative

• quantitative

How do descriptive and inferential statistics differ?

• Descriptive statistics only attempt to describe data, while inferential statistics attempt to make predictions based on data.

• Inferential statistics only attempt to describe data, while descriptive statistics attempt to make predictions based on data.

• Descriptive statistics are more computationally sophisticated than inferential statistics.

• Inferential statistics are more computationally sophisticated than descriptive statistics.