SOLUTION: To compare two different pipe lengths, a mechanic conducts 32 tests for each type. The results for type A pipes are x1 = 44 feet with s1 = 4.3 feet and for type B pipes are x2 = 47

Algebra ->  Probability-and-statistics -> SOLUTION: To compare two different pipe lengths, a mechanic conducts 32 tests for each type. The results for type A pipes are x1 = 44 feet with s1 = 4.3 feet and for type B pipes are x2 = 47      Log On


   

Question 460429: To compare two different pipe lengths, a mechanic conducts 32 tests for each type. The results for type A pipes are x1 = 44 feet with s1 = 4.3 feet and for type B pipes are x2 = 47 feet with s2 = 4.0 feet. At alpha = .10 can the mechanic support the claim that the mean pipe lengths are di fferent for the two types of pipes?
I found the null hypothesis to be equal to while the alternative hypothesis was not equal to. I got the difference of the 2 means to be -3. I'm not sure where to go from here.
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
sigma%28x1-x2%29=sqrt%28%28s1%5E2%2Fn1%5E2%29%2B%28s2%5E2%2Fn2%5E2%29%29
=sqrt%28%284.3%5E2%2F32%5E2%29%2B%284%5E2%2F32%5E2%29%29
=.1835
.
z=%28x1-x2%29%2Fsigma%28x1-x2%29=%28%284.3-4.0%29%2F.1835%29=1.63
.
For a confidence level of 0.10 the region of rejection begins at 1.64 so the mechanic cannot support the claim that the mean pipe lengths are di fferent for the two types of pipes.
.
Ed