Measures of Central Tendency and Measures of Variability

Question 1

What is the median?

Answer 1

• the middle number when the scores (also called raw data) are arranged in order
• If there are an even number of data, we must take the mean of the middle two scores.

Question 2

What is the mode?

Answer 2

the raw score that appears the most in a set of data

Question 3

What is the range?

Answer 3

• gives us the spread of the data

- considered a Measure of variability

Question 4

Why isn’t range the strongest indicator of variability?

Answer 4

range only takes into account the highest and lowest numbers in a set of data

Question 5

What is the variance?

Answer 5

• a stronger measure of variability since it takes into account all of the raw scores in a set of data
• provides information about the spread of the data around the mean

Question 6

What is standard deviation?

Answer 6

square root of the variance