How often do college students engage in particular activities using their cellphones? A researcher

surveyed a random sample of 164 college students. The students were asked to indicate the number of

minutes they spent texting per day. The average number of minutes spent texting per day was 94.6

minutes, with a standard deviation of 65.3 minutes. Use this information to answer the following

questions.

1. What would we call the numbers 94.6 and 65.3?

A. Both numbers are statistics.

B. Both numbers are parameters.

C. 94.6 is a statistic and 65.3 is a parameter.

D. 94.6 is a parameter and 65.3 is a statistic.

A. Both numbers are statistics.

Explanation:

The number 94.6 is an average measure from a sample. It is the mean of a sample.

The number 65.3 is the standar deviation of a sample.

Then, thus numbers are used to estimate the values of the population.

The true mean and the standard deviation of a population are constant numbers; many times unknown (specially when the population is too big). As, those values are parameters of the population, regardless they are known or not.

When, they are not known, the statistician must estimate them. The statistician does it using samples (one or more). Such estimated values are not parameter but statistics.

Statistics are values for a sample and may (in general will) vary from sample to sample, while the parameters, which belong to the population are fixed values.