Question

Question #e0a65

Answer 1

Using a Standard Normal Table:

Pr(-1.2 < Z < 0.038) = 0.4

Explanation:

The "standard" normal distribution (also called the z-distribution) is a bell-shaped curve that is perfectly symmetrical around the point z = 0. The "area" under the curve from z = `-oo` to z = `+oo` is equal to 1.00 .

In this problem, you are given that the area is equal to 0.4 between z = -1.2 and z = k. Your task is to find k.

STEP 1:
Using a standard normal table (usually in the back of your statistics textbook) to look up the area between [-1.2, 0] which can also be written as Pr(-1.2 < Z < 0) = 0.3849.

STEP 2:
If the total area for this problem is 0.4, then the area between [0, k] must be equal to 0.4 - 0.3849 = 0.0151.

STEP 3:
Using a standard normal table (looking within the body of the table), find the area for the probability Pr(0 < Z < k) = 0.0151. You should find k = 0.038

Hope that helped!