in a large population, 72% of the households have cable tv. a simple random sample of 100 households is to be contacted and the sample proportion computed. what is the probability that the sampling distribution of sample porportions is less than 68%? a) 0.1865 b) 0.3187 c) 0.0932 d) 0.6813 e) 0.8135 f) none of the above