Specifications call for the wall thickness of two-liter polycarbonate bottles to average 4.0 mils. a quality control engineer samples 7 two-liter polycarbonate bottles from a large batch and measures the wall thickness (in mils) in each. the results are: 3.999, 4.037, 4.116, 4.063, 3.969, 3.955, and 4.091. it is desired to test h0 : μ = 4.0 versus h1 : μ = 4.0. a. make a dotplot of the seven values. b. should a student’s t test be used to test h0? if so, perform the test. if not, explain why not. c. measurements are taken of the wall thicknesses of seven bottles of a different type. the measurements this time are: 4.004, 4.225, 3.924, 4.052, 3.975, 3.976, and 4.041. make a dotplot of these values. d. should a student’s t test be used to test h0 : μ = 4.0 versus h1 : μ ≠ 4.0? if so, perform the test. if not, explain why not.