The Gallup organization conducted a poll of 1038 randomly se

The Gallup organization conducted a poll of 1038 randomly selected adults and found that 52% said that secondhand smoke is

Solution

a) The 52% is a statistic, because it is a measurement based upon a sample (as opposed to being based upon the entire population of adults, in which case it would be a parameter).

b) I think it is a normal distribution, because, by the Central Limit Theorem, a probability distribution tends to the normal distribution as the number of identically distributed (same type of population) independent random variables increases (i.e., as the sample size increases; 1038 is a pretty large sample).

c) Yes, 2000 is better because having more observations decreases the sample variance, which makes the results more precise.