Measures of Dispersion

Question 1

How do you calculate the z score?

Answer 1

Take away a particular score from the mean set of scores and divide that by the standard deviation

Question 2

How do you interpret a z score?

Answer 2

The larger the number (either positive or negative) the more atypical a score is of the typical score in the data set

Question 3

What is an advantage of using a z score?

Answer 3

Variables can be compared to one another or combined when they are put into Z scores. Especially if the variables are all measured in different units

Question 4

What is the standard normal distribution?

Answer 4

Frequency curve of z scores to show if there is a bell curve or a positive or negative distribution
Mean of 0
Standard deviation of 1
See the extreme values and can compare data
68% data lies within 1 SD
95% data lies within 2 SDs
99.7% data lies within 3 SDs

Question 5

Why are z scores used?

Answer 5

Z scores show us
- The mean of the distribution
- The standard deviation of the distribution
- The distribution is either bell shaped or normal