1. Normal distributions are symmetrical.

3. Only a little bit of the curve lies to the left of z, and most of it lies to the right.

9. Do the steps for normal problems: Find the z scores, sketch them on the curve and shade between them, find the shaded area by getting the areas (from the table) and subtracting.

14. See the bottom of the chart for z values that are off the chart (like z = 4 in this case).

16. Convert 5.2% to a decimal so you can look it up in the table.

19. Look up the complement of 8% to find the area above 8%.

23. The middle 98% of the curve is 49% below the middle and 49% above the middle.

29. For (a), find the percentage for x = 36 months (see 6-B), and for (b), find the number of months x for the bottom 10% (see 6-C).

36. Convert 7200 and 8900 to z scores so you can look up their percentages.