7.A consumer protection agency is com paring he work of two electrical contractors. The agency plans to inspect residencesin which each of these contractors has done the wiring in order to estimate the d ifference in the proportions of residencesthat are electrically deficient. Suppose the proportions of residences with deficient work are expected to be about . 2 for bothcontractors. How many homes should be sampled in order to estimate the difference in proportions using a 90% confidenceinterval of width . 5?)”
(A)