the percentage of cell phone who used their cell phone to send or receive text messages was 80%. If p is the proportion of cell owners who used their phone to text, then what was the mean for p̂?

Question

A polling firm contacted a simple random sample of 1100 people chosen from the population of cell phone owners.

Answer 1

The question is little bit vague but the sampling distribution of p-hat(sample proportion) always has mean as p (population proportion).

In this case np=1100*.8=880 and n(1-p)=1100*.2=200 both are more than 15. So the above result holds.