a:8 b:2 c:5 d:6

1.) Plastic sheets produced by a machine are periodically monitored for possible fluctuations in thickness. If the true variance in thicknesses exceeds 4*a square millimeters, there is cause for concern about product quality. Thickness measurements for a random sample of 10 sheets produced in a particular shift were taken, giving the following results (in millimeters): 8*a*b 7*c*b 6*a*d 9*a*c 5*b*d 228 225 228 229 230 Quality department claims that there is no concern about product quality. Based on this information; a) State your hypothesis H0 and H1. b) State the decision rule (exactly as in the book), sample statistics, table value and test statistic (with the exact formula) in the same order as in the extra-solved examples on hypothesis testing. c) Test, at the X% significance level, the null hypothesis that there is no concern about product quality (please set X=10)