”Deep hole” drilling is a family of drilling processes used when the ratio of hole depth to hole diameter exceeds 10. Successful deep hole drilling depends on the satisfactory discharge of the drill chip. An experiment was conducted to investigate the performance of deep hole drilling when chip congestion exists (Journal of Engineering for Industry, May 1993). The length (in millimeters) of 50 drill chips resulted in the following summary statistics: y̅ = 81.2 mm, s = 50.2 mm. Conduct a test to determine whether the true mean drill chip length, μ, differs from 75 mm. Use a significance level of α = .01.