Question

Problem 5, (25pts) To assess the quality of medical strips, used to test the level of glucose in the blood, one must control the consistency, that is resulted from the same sample if many repeated measures are obtained from that sample. If the variance in the results is too high the strip is considered as inconsistent and lower quality. Two possible strips are tested and compared with each other strip A and strip B and the results were recorded as follows Type Sample SizeSample Variance 16 2.09 21 Type B is a new version of type A strips. Do you believe that type B strips is with better quality than type A. Prove your answer at 10% level of significance. Use the rejection region method (15pts) and the p-value method (10pts)

Answer 1

n1 = 16 , n2= 21 , variance1 = 2.09, variance2 = 1

We may conclude that the type B strip is of better quality than type A.

This corresponds to a right-tailed test, for which a F-test for two population variances needs to be used Rejection Region Based on the information provided, the significance level is α-0.10, and the the rejection region for this right-tailed test is R F:F> F 1.845) The F-statistic is computed as follows: -4부: 男·01) 82ーーーミ2.09 2.09 " Decision about the null hypothesis Since from the sample information we get that F-2.09 > FU = 1.845, it is then concluded that the null hypothesis is rejected. Conclusion It is concluded that the null hypothesis Ho is rejected. Therefore, there is enough evidence to claim that the population variance σ, is greater than the population variance σ, at the α-0.10