Question

As a part of preparation for this week 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 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 real situation where this technique can be applied. For instance see Chapter 6 section 6.3 example 6.11 on page 270 of eText: Intelligence Quotients example. Create your own scenario and values.

Answer 1

Answer:-

Given that:-

The length of life of an instrument produced by a machine has a normal distribution with a mean of 11 months and standard deviation of 2 months.

Now we can set up a situation Like this "The probability of this instrument will last between 7 months and 14 months."

Here A=7, B=14  ,  

We need to find

Now

Normal distribution is symmetric.