The specification for the pull strength of a wire that conne

The specification for the pull strength of a wire that connects an integrated circuit to its frame is 10g or more. In a sample of 85 units made with gold wire, 68 met the specification, and in a sample of 120 units made with aluminum wire, 105 met the specification.

Solution

We use p=0.5 as estimated.

Given a=1-0.95=0.05, Z(0.025) = 1.96 (from standard normal table)

So n=(Z/E)^2*p*(1-p)

=(1.96/0.01)^2*0.5*0.5

=9604