Statistics (Normal Disribution)

Chapter 6: More Practice With Normal Distributions.

As a part of the preparation for this week’s test, let’s practice with another case related to the Normal distribution. Assign your numbers for mean μ and standard deviation σ. Then select a number “A” below mean μ, and a number “B” above mean μ. Use Appendix Table for the Normal Distribution to find the probability that x is between A and B: P (A < x < B).

Here are the steps to follow:

convert A to z score (let’s call it za),

convert B to z score (let’s call it zb).;

From Appendix table find area under curve to the left of za and to the left of zb.

That will give you P (z < za) and P (z < zb).

If za or zb are not in the table, change your A or B. Use formula:

P (A < x < B) = P (za < z < zb) = P (z < zb) – P (z < za)

Don’t just assign numbers, make an example from a real situation where this technique can be applied. For instance, see Chapter 6 section 6.3 example 6.11 on page 281 of eText: Intelligence Quotients example. Create your own scenario and values.