Chapter 5: Z-scores Activity #1

Listed below are the descriptive statistics of the class scores on a self-efficacy scale, with higher scores meaning higher perceived self-efficacy:

= 32, = 3

1. Calculate the z-scores and describe their location in words for the following raw scores of self-efficacy:

a. X = 23

"This score is -3 (number) standard deviations below (above/below) the mean."

Is this score considered typical or extreme for this set of scores? ____________

b. X = 35

"This score is ____ (number) standard deviations ____ (above/below) the mean."

Is this score considered typical or extreme for this set of scores? ____________

c. What score lies atz = -1 (1 standard deviation below the mean)?

2. Imagine the mean and standard deviation of the scores changed. Calculate the z-scores and describe their location with the following class score descriptive statistics:

= 25, = 5

a. X = 23

"This score is _____ (number) standard deviations ______ (above/below) the mean."

Is this score considered typical or extreme for this set of scores? _________

b.X = 35

"This score is ____ (number) standard deviations ______ (above/below) the mean."

Is this score considered typical or extreme for this set of scores? _________

c. What score lies at z = +1 (1 standard deviation above the mean)?