1. IQ scores are standardized to produce a normal distribution with a mean of µ = 100 and a standard deviation of σ = 15. Find the proportion of the population in the following IQ category: IQ between...

1. IQ scores are standardized to produce a normal distribution with a mean of µ = 100 and a standard deviation of σ = 15. Find the proportion of the population in the following IQ category:

 IQ between 85 and 109

2.

IQ scores are standardized to produce a normal distribution with a mean of µ = 100 and a standard deviation of σ = 15. Find the proportion of the population in the following IQ category:

 IQ between 115 and 130

3.What z-score values separate the middle 99% of the distribution from the rest of the scores?

4.What z-score values separate the middle 50% of the distribution from the rest of the scores?

5. What z-score value separates 15% of the distribution in the tail on the right (i.e., the top 15% of the distribution) from the rest of the distribution ?