SOLUTION: "A certain rice miller says that the average weight of a cavan of rice is 50 kilograms with a standard deviation of 5 kilograms. A retailer sampled 20 cavan of this rice and got an

Algebra ->  Probability-and-statistics -> SOLUTION: "A certain rice miller says that the average weight of a cavan of rice is 50 kilograms with a standard deviation of 5 kilograms. A retailer sampled 20 cavan of this rice and got an      Log On


   



Question 1074660: "A certain rice miller says that the average weight of a cavan of rice is 50 kilograms with a standard deviation of 5 kilograms. A retailer sampled 20 cavan of this rice and got an average weight of 46.6 kilograms. Is this claim of the rice miller valid using the 5% level of significance?"
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
assume normality and random sample; also assume sd is unbiased estimator of true sd
test statistic is (xbar-mean)/(s/sqrt(n)) with critical value for t(0.975 df=19) of 2.093, absolute value.
(46.6-50)/(5/sqrt(20)=-3.4*sqrt(20)/5=-3.041
This absolute value of this is greater than the critical value, so one would reject Ho and the claim at the 5% level.