Question

A professor at Iowa State has a dataset consisting of the unemployment rates for all 99 counties in the state of Iowa. The professor asks her students to conduct a statistical analysis of the data and reiterates that they may use any approach they deem necessary. One of the students recalls that the normal distribution is a widely used density within the world of statistics and decides to conduct the analysis assuming all 99 counties’ unemployment rates follow a Normal distribution with mean µ and standard deviation σ. Use the data found in Unemployment.jmp to answer the following questions regarding the student’s analytic approach. Unemployment rates are reported as a (proportion × 100), e.g. 0.032 is reported as 3.2(%).

1. Assume the unemployment rates follow a Normal distribution with mean 4.10(%) and a standard deviation of 2.60(%). What is the unemployment rate such that only 5.05% of all counties have an unemployment rate smaller than that value? Report the unemployment rate with 2 decimal places and without the unit, e.g. report the rate 4.5678(%) as 4.57.

Answer 1