# Statdisk Instructions for Chapter 5 Technology Exercise

## Finding Areas (Question 1)

- Choose Analysis / Probability Distributions / Normal
- Enter your z-score into the box labeled z Value.
- Leave the cumulative area from the left box blank.
- Click Evaluate

Statdisk returns the area to the left, the area to the right, and the 2-tailed
(twice the smaller value) areas.

## Finding Z-Scores (Question 2)

- Choose Analysis / Probability Distributions / Normal
- Leave the z Value box blank
- Enter the appropriate value into the cumulative area from the left box
- If your area is to the left of the z-score, enter that value
- If your area is to the right of the z-score, subtract the area from
one and then enter that value
- If your area is something else, you'll have to find the area to the
left and enter that value

- Click Evaluate

## ACT Test Scores (Question 3)

This question is like questions 1 and 2 except we are no longer working with
a standard normal distribution.

Use the formula for standardizing a variable from chapter 2 to either convert
to a raw score to a z-score or from a z-score to a raw score.

That formula is z-score = (value - mean) / stdev