Statistics

Determine the width of the class

• 5

• 4

• 3

• 6

A researcher is interested in the travel time of Utrecht University students to college. A group of 50 students is interviewed. Their mean travel time in 16.7 minutes. For this study the mean of 16.7 minutes is an example of a(n)

• Parameter

• Statistic

• Population

• Sample

Answer explanation

parameter is a number that summarizes some aspect of the population as a whole.

A statistic is a number computed from the sample data

A researcher is curious about the IQ of students at the Utrecht University. The entire group students is an example of a:

• Parameter

• Statistic

• Population

• Sample

Compare voter satisfaction levels between people assigned to use either paper ballots or touchscreen machines.

• Experiment
• Observational Study

Determine which brands of orange juice people prefer. The people are randomly chosen at the supermarket and are asked to taste both brands without knowing which brand they are drinking.

• Experiment
• Observational Study

Determine if people who take vitamin C every day are less likely to get colds.

• Experiment
• Observational Study

A teacher asks her students to write down all they eat in a day and then calculate the total number of calories consumed. 

• Experiment
• Observational Study

Is diet or exercise effective in combating insomnia? Some believe that cutting out desserts can help alleviate the problem, while others recommend exercise. Forty volunteers suffering from insomnia agreed to participate in a month-long experiment. Half were randomly assigned to a special no-desserts diet; the others continued desserts as usual. Half of the people in each of these groups were randomly assigned to an exercise program, while the others did not exercise. Those who ate no desserts and engaged in exercise showed the most improvement. 

• Observational Study
• Experiment

Researchers have linked an increase in the incidence of breast cancer in Italy to dioxin released by an industrial accident in 1976. The study identified 981 women who lived near the site of the industrial explosion and were under age 40 at the time. Fifteen of the women had developed breast cancer, at an unusually young average age of 45. Medical records showed that these women had heightened concentrations of dioxin in their blood, and that each 10-fold increase in dioxin level was associated with a doubling of the risk of breast cancer. (Science News, Aug. 3, 2002)

• Observational Study
• Experiment

A gray elephant stampeding across the Savannah is an example of a observation.

• Quantitative

• Qualitative

• Neither quantitative nor qualitative