Chapter 6: More Practice With Normal Distributions. As a part of preparation for this week’s test, let’s practice with another case related to the Normal distribution. Assign your numbers for mean ? and standard deviation ?. Then select a number “A” below mean ?, and a number “B” above mean ?. Use Appendix Table for the Normal Distribution to find the probability that x is between A and B: P (A < x < B). Here are 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.