Teacher Salaries. Data on salaries in the public school system are published annually in Ranking of the States and Estimates of School Statistics by the National Education Association. The mean annual salary of (public) classroom teachers is $55.4 thousand. A random sample of 90 classroom teachers in Ohio yielded the annual salaries, in thousands of dollars, presented on the WeissStats site. Use the technology of your choice to perform the following tasks.

a. Obtain a normal probability plot, boxplot, histogram, and stemand-leaf diagram of the data.

b. Based on your results from part (a), can you reasonably apply the one-mean z-test to the data? Explain your reasoning.

c. At the 5% significance level, do the data provide sufficient evidence to conclude that the mean annual salary of classroom teachers in Ohio is greater than the national mean? Assume that the standard deviation of annual salaries for all classroom teachers in Ohio is $9.2 thousand.