Lesson Quiz 2-3: Psychological Research Methods and Statistics

Statistics is the branch of mathematics used to organize and evaluate data.

• True

• False

Both the mode and the median are measures of correlation.

• True

• False

A positive correlation indicates that there is a cause-and-effect relationship between two variables.

• True

• False

The mean of the scores 10, 13, 16, and 17 is 15.

• True

• False

A normal curve is symmetrical.

• True

• False

Central tendency is a measure that tells something about

• the results of a cross-sectional study.

• the average score of participants given the same test.

• the validity of questions on a questionnaire.

• test scores when they are shown in a straight line graph.

Which of the following uses rectangles to show frequency distribution?

• frequency polygon

• histogram

• normal curve

• skewed distribution

If you want to calculate the standard deviation for a set of data, you could begin by

• creating a frequency polygon.

• determining the median.

• calculating the variance.

• calculating the correlation coefficient.

Inferential statistics are important because they

• can be used to describe the characteristics of sample data, such as its range and mean.

• can be used to calculate the variability of a sample.

• allow researchers to determine how often a particular score or observation has occurred in a sample.

• allow scientists to make generalizations about the population from which a sample was taken.

The range of a(n) ____________________ must be between +1 and −1.

• standard deviation

• mode

• frequency distribution

• Pearson correlation coefficient