In: Statistics and Probability
Two catalysts are being considered for a chemical process. Sixteen batches were completed using Catalyst 1, providing an average yield of ?̅1 = 84 and a standard deviation of ?1 = 1.87. Thirteen batches were run with Catalyst 2, and a mean yield of ?̅2 = 89 was found, along with ?2 = 1.48. Assume the underlying yield data are Normally distributed.
(a) Is it believable that the variances of the two populations differ? Use the appropriate hypothesis test with α = 0.05.
(b) Based on your answer to part (a), calculate the appropriate 99% CI to test if the mean yields for the two catalysts differ. Give your conclusions with context.
(c) If 4 batches made with Catalyst 1 were found to be below the yield specification, and 3 batches made using Catalyst 2 were below specification, calculate the 95% CI to determine if the proportion of batches that fall under specification is the same for the two Catalysts.
a)
b)
c)
since 0 is present in confidence interval
there is not significant difference in proportion