How much oil wells in a given field will ultimately produce is key information in deciding whether to drill more wells. Following are the estimated total amounts of oil recovered from 64 wells in the Devonian Richmond Dolomite area of the Michigan basin, in thousands of barrels.
Take these wells to be a Simple Random Sample of wells in this area.
21.71 53.2 46.4 42.7 50.4 97.7 103.1 51.9
43.4 69.5 156.5 34.6 37.9 12.9 2.5 31.4
79.5 26.9 18.5 14.7 32.9 196 24.9 118.2
82.2 35.1 47.6 54.2 63.1 69.8 57.4 65.6
56.4 49.4 44.9 34.6 92.2 37.0 58.8 21.3
36.6 64.9 14.8 17.6 29.1 61.4 38.6 32.5
12.0 28.3 204.9 44.5 10.3 37.7 33.7 81.1
12.1 20.1 30.5 7.1 10.1 18.0 3.0 2.0
Construct a 95% confidence interval for the mean amount of oil recovered from all wells in this area using t procedures.
Make a histogram of the data and discuss the shape, center, and spread. A computer-intensive method that gives accurate confidence intervals without assuming any specific shape of the distribution gives a 95% confidence interval of 40.28 to 60.32. How does the t interval that you constructed compare with this interval? Should the t procedures be used with this data?