Statistics Chapter 4

Question 1

What two aspects of the data determine which measure of central tendency to use?

Answer 1

1. The scale of measurement used so that the summary makes sense given the nature of scores.
2. The shape of the frequency distribution the scores produce so that the measure accurately summarizes the distribution.

Question 2

What is the mode, and with what type of data is the most appropriate?

Answer 2

It is the most frequently recurring score and it is usually used to summarize nominal data.

Question 3

What is the median, and with what type of data is it most appropriate?

Answer 3

It is the middle score or the 50th percentile and is used to summarize ordinal or highly skewed interval or ratio scores.

Question 4

What is the mean, and with what type of data is the most appropriate?

Answer 4

The mean (or the average) is the score located at the mathematical center of a distribution, and is used to describe the central tendency of a normal distribution of interval or ratio scores.

Question 5

Why is it inappropriate to use the mean with a skewed distribution?

Answer 5

Because here the man is not near most of the scores.

Question 6

Which measure of central tendency is used most often in behavioral studies, and why?

Answer 6

The mean because it includes every score, so it does not ignore any information in the data.

Question 7

What two pieces of information about the location of a score does a deviation score convey?

Answer 7

Deviations convey: a) whether a score is above or below he mean and b) how far the score is from the mean.

Question 8

Why do we use the mean of a sample to predict any score that might be found in that sample?

Answer 8

Because it is central, typical score, we act as if all the scores were the mean score, and so we predict that score every time.

Question 9

What does a measure of central tendency indicate?

Answer 9

It indicates where on a variable most scores tend to be located.