Exam 1: Statistics, Data, and Statistical Thinking

In a survey of 5000 high school students, 14% of those surveyed read at least one best-seller each month. Give an example of a descriptive statement and an inferential statement that could be made based on this information.

Because of the possible legal consequences, many people in a sample of the U.S. population chose not to participate in a survey regarding illegal drug use. What type of problem has occurred?

Which of the following is not the job of a statistician?

A measure of reliability is an important element of a descriptive statistical problem.

A study in the state of Georgia was conducted to determine the percentage of all community college students who have taken at least one online class. 1500 community college students were contacted and asked if they had taken at least one online class during their time at their community college. These responses were then used to estimate the percentage of all community college students who have taken at least one online class. What type of variable is being collected?

In an observational study, the researcher exerts strict control over the units in the study.

Parking at a university has become a problem. University administrators are interested in determining the average time it takes a student to find a parking spot. An administrator inconspicuously followed 270 students and recorded how long it took each of them to find a parking spot. Identify the variable of interest to the university administration.

Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 250 students and carefully recorded their parking times. Identify the experimental unit of interest to the university administration.

A quality inspector tested 37 copiers in an attempt to estimate the average failure rate of the copier model. His study indicated that the number of failures decreased from two years ago, indicating an increase in the reliability of the copiers. Describe the variable of interest to the inspector.

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

An assembly line is operating satisfactorily if fewer than 2% of the phones produced per day are defective. To check the quality of a day's production, the company randomly samples 50 phones from a day's production to test for defects. Define the population of interest to the manufacturer.

The way in which an interviewer asks a question about political party affiliation causes respondents to answer that they have no affiliation when they actually do. What type of problem has occurred?

Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 250 students and carefully recorded their parking times. Identify the variable of interest to the university administration.

Which of the following is not typically an element of inferential statistical problems?

A middle school was interested in surveying their students to find out opinions about the schools media center. To facilitate data collection, the homeroom period was extended 30 minutes to allow everyone in the school ample time to respond to a short questionnaire. Unfortunately, it was learned after the surveys had been completed that all honors students in the middle school were on an all-day field trip and away from school for the entire day. The exclusion of their input into the survey would be considered which type of sampling problem?

Parking at a large university has become a very big problem. University administrators are interested in determining the average parking time (e.g. the time it takes a student to find a parking spot) of its students. An administrator inconspicuously followed 250 students and carefully recorded their parking times. What type of variable is the administration interested in collecting?

Give an example of unethical statistical practice.

Which type of problem has occurred when inaccuracies exist in the values of the data recorded?

What method of data collection would you use to collect data for a study where a drug was given to 51 patients and a placebo to another group of 51 patients to determine if the drug has an effect on a patient's illness?

A researcher studying malnutrition among children in a developing country collected weights of a random sample of children using a scale that she had set to give weights 2.5 kilograms less than the actual weight. Which statement best describes this situation?