Elongation measurements are made on 10 pieces of steel, five of which were treated with Method A (aluminum plus calcium) and the remaining five with Method B (aluminum only). It is conjectured that the addition of calcium will improve elongations by at least 1%. The results of the measurements are (in percent)
|
Method A
|
34
|
27
|
30
|
26
|
33
|
|
Method B
|
28
|
29
|
25
|
23
|
30
|
A. Test the hypothesis sigmaA^2 = sigmaB^2 at the 5% level of significance.
B. Using the result in (a), test the hypothesis
Ho= muA-muB = 1% versus H1= muA-muB > 1%