A study is conducted to compare the tensile strength of two

A study is conducted to compare the tensile strength of two types of roof coatings. It is thought that, on the average, butyl coating s are stronger than acrylic coatings. The following data are obtained: Butyl Acrylic 16 nA 16 300.22 319.11 sa 1298.47 si 472.71 Assume independent samples and both samples are from normally distributed populations Use a 0.05 (a) hat are the hypotheses? (b) Calculate the test statistic: (c) What is the P value of the test? If needed, the Smith-Satterthwaite procedure results in y df 17. d) what is your decision about the null hypothesis

Solution

a)

Null Hypothesis : mu ( Butyl ) = mu ( Acrylic )

Alternate Hypothesis : mu ( Butyl ) > mu ( Acrylic )

b)

Test-static = (319.11 - 300.22)/sqrt( (1298.47)^2 /16 + (472.71)^2 /16 ) = 0.054 Answer

c)

It is a two tailed test ,

P-value = 2 * (1-0.5199 ) = 0.9602 Answer

d) Failed to reject null hypothesis