Two different analytical tests can be used to determine the impurity level in steel alloys. Eight specimens are tested using both procedures, and the results are shown in the following tabulation.
Specimen Test 1 Test 2
1 1.2 1.4
2 1.3 1.6
3 1.5 1.5
4 1.4 1.3
5 1.7 2.0
6 1.8 2.1
7 1.4 1.7
8 1.3 1.6
If the mean from Test 1 is 0.1 less than the mean from Test 2, it is important to detect this with probability at least 0.90. Was the use of 8 alloys an adequate sample size? If not, how many alloys should have been used?
