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.