AP Psychology Statistics

A frequency distribution

• is a way to present data visually in a table
• depicts a correlation between two variables using a histiogram
• is the same thing as a scattergram
• typically lists the frequency of each score on the horizontal axix

You psychology professor wants to describe the average score on your first psychology test.  Which measure of central tendency is your professor most likely to use? 

• mean
• median
• mode 
• harmonic mean

Which measure of central tendency is obtained by adding all the scores and dividing that total by the number of scores?

• mode
• median
• mean
• range

In a strongly skewed distribution, the best indicator of central tendency is usually the

• mean
• median
• mode
• standard deviation

When scores are "bunched up"in the center of a distribution, the

• mean will be relatively low

• standard deviation will be relatively low

• correlation coefficiaent will be a negative number

• standard deviation will be relatively high

The standard deviation

• indicates the average difference between each score in a group and the mean for that group of scores
• reveals the degree of skew for a a group of scores 
• is sensitive to scores at the extremes of a distribution of scores
• is used to determine whether a data set is positively or negatively skewed

The symmetric, bell shaped curve that represents the pattern in which many human characteristics are dispersed in the population is known as

• scatter plot
• normal distribution
• frequency polygon
• histogram

Julia has an IQ of 130.  If the mean for IQ is 100 with a standard deviation of 15, what percentage of the population has an IQ greater that Julia's (assume a normal distribution)?

• 0 percent
• 2.5 percent
• 32 percent
• 50 percent