A company that manufactures two grades of steel wire wishes to compare the
breaking strengths, measured' in Newtons (N)' of two wires' A random
sample of 10 pieces of grade A wire and 8 pieces of grade B wire were tested'
Grade A: 80.2 80.1 79.8 79.6 80.2 80.4 81.0 80.4 80.3 79.9
Grade B: 80.1 80.0 79.6 80.0 80.2 79.6 80.4 80.1
Assuming that the breaking strengths of the wire are normally distributed'
(i)Test at the 5% level that the results are more variable for Grade A
than for Grade B.
(ii) Test at the 1% level that the mean breaking strength is higher for
Grade A than for Grade B'
thanks for any help