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
1. If your area is to the left of the z-score, enter that value
2. If your area is to the right of the z-score, subtract the area from one and then enter that value
3. 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