With reference to the previous exercise, construct a 90% confidence interval for the true population mean quantity of gravel in concrete mixes.

Data From Previous Exercise

7.1 A construction engineer collected data from some con- struction sites on the quantity of gravel (in metric tons) used in mixing concrete. The quantity of gravel for n = 24 sites 4861 5158 8642 2896 7654 9891 8381 6215 1116 7918 2313 8114 3517 8852 5712 4312 8023 1215 3598 2429 8211 4613 9168 6819 has x = 5818 tons and s = 2697 tons. What can one assert with 90% confidence about the maximum error if x = 5818 tons is used as a point estimate of the true population mean amount of gravel used in con- crete mixes?