IMSE 317/ BENG 364 - Fall 2015 HW #5 Due on Dec. 09, 2015 Problem 1: Use Minitab The impurity level (in ppm) is routinely measured in an intermediate chemical product. The 22 observations are: 2.4, 2.5, 1.7, 1.6, 1.9, 2.6, 1.3, 1.9, 2.0, 2.5, 2.6, 2.3, 2.0, 1.8, 1.3, 1.7, 2.0, 1.9, 2.3, 1.9, 2.4, 1.6 a) What is the 95% confidence interval for the population mean? b) With the Minitab output, do you have strong evidence to support the claim that the mean impurity level is less than 2.2 ppm with =0.01? c) What is the P-value? Problem 2: A particular type of gasoline is supposed to have a mean octane rating greater than 85 (out of 100). Assume the octane ratings follow the normal distribution. 10 measurements are taken of the octane rating, as follows: 90.1, 88.8, 89.5, 91.0, 86.0, 87.9, 92.1, 89.0, 88.5, 92.5 a) b) c) Is the true standard deviation of the octane rating significantly less than 2? Use rejection area criterion for this question. ( = 0.05). Find the P-value of this test. Use interval to test whether the true mean of octane rating is really greater than 85 based on the 10 collected measurements listed above. ( = 0.01)