Question: The file Concrete1 contains the compressive strength in thousands of

The file Concrete1 contains the compressive strength, in thousands of pounds per square inch (psi), of 40 samples of concrete taken two and seven days after pouring. (Data ­extracted from O. Carrillo Gamboa and R. F. Gunst, “Measurement Error Model Collinearities,” Technometrics, 34 (1992): 454– 464.)
a. At the 0.01 level of significance, is there evidence that the mean strength is lower at two days than at seven days?
b. What assumption is necessary about the population distribution in order to perform this test?
c. Find the p value in (a) and interpret its meaning.

View Solution:


Sale on SolutionInn
Sales0
Views84
Comments
  • CreatedJuly 16, 2015
  • Files Included
Post your question
5000