Chapter 5- Z score: Lecture

Question 1

How is Z-score a descriptive statistic?

Answer 1

they describe exactly where each individual score is located

Question 2

What is the advantage to standardizing the z-scores?

Answer 2

• you can compare distributions with different scales
• you can compare relative distances from the mean

Question 2

How is Z score an inferential statistic?

Answer 2

• Can determine whether a specific sample is representative of the population
• can determine whether a specific score is representative of a sample

z scores above or below 2 are typically considered extreme/unrepresentative (the top and bottom 2%)

Question 2

Z scores as a standardized distribution

Answer 2

• transform each x score into a z- score
• distribution will always have M=0 and s=1
• does not change the shape of the raw distribution
• does not change the location of any individual score relative to others (just changes the scale)