The department of economic and community development (decd) reported that in 2009 the average number of new jobs created per county was 450. the department also provided the following information regarding a sample of 5 counties in 2010. assume the population is normally distributed. county new jobs created in 2010 bradley 410 rhea 480 marion 407 grundy 428 sequatchie 400.
a. compute the sample average and the standard deviation for 2010.
b. we want to determine whether there has been a significant decrease in the average number of jobs created. provide the null and the alternative hypotheses.
c. compute the test statistic.
d. at α = 0.05, test the hypotheses.
e. build a 95% confidence interval about the population mean given the sample information above.
f. does the result from the interval support your test conclusion from part (d)? explain.