Recall (from Exercise 2.26) that the mean base salary of a software engineering manager is $126,417 (Electronic Design’s 2012 Engineering Salary Survey). Assume the distribution of base salaries for all software engineers is mound-shaped with a variance of 225,000,000. Sketch the distribution, showing the intervals μ ± σ s, μ ± 2σ and μ ± 3σ on the graph. Estimate the proportion of software engineering managers with base salaries in each interval.

**Data from Exercise 2.26**

According to Electronic Design’s 2012 Engineering Salary Survey, the mean base salary of a software engineering manager is $126,417—the highest mean among all types of engineers. In contrast, a manufacturing/ production engineer has a mean base salary of $92,360. Assume these values are accurate and represent population means. Determine whether the following statements are true or false.