Problem 2. An article in Fire Technology investigated two different foam-expanding agents that can be used in the nozzles of fire-refighting spray equipment. A random sample of five observations with...

Extracted text: Problem 2. An article in Fire Technology investigated two different foam-expanding agents that can be used in the nozzles of fire-refighting spray equipment. A random sample of five observations with an aqueous film-forming foam (AFFF) had a sample mean of 4.1 and a standard deviation of 0.6. A random sample of five observations with alcohol-type concentrates (ATC) had a sample mean of 6.6 and a standard deviation 0.8. a. Can you draw any conclusions about differences in mean foam expansion? Use a=0.05. Assume that both populations are well represented by normal distributions with the same standard deviations. Find the value of the test statistic. Suppose that the null hypothesis is H: µ -4=A, =0. What is your conclusion about differences in mean foam expansion? b. Find a 95% confidence interval on the difference in mean foam expansion of these two agents.