Pull-strength tests on 10 soldered leads for a semi conductor device yield the following results in pounds force required to rupture the bond:
19.8 12.7 13.2 16.9 10.6
18.8 11.1 143 17.0 12.5
Another set, of 8 leads was tested after encapsulation to determine whether the pull strength has been increased by encapsulation of the device, with the following results: 24.9 22.8 23.6 22.1 20.4 21.6 21.8 22.5 Comment on the evidence available concerning equality of the two population variances.