Question

Many people think that a national lobby's successful fight against gun control legislation is reflecting the will of a minority of Americans. A previous random sample of 4000 citizens yielded 2250 who are in favor of gun control legislation. How many citizens would need to be sampled if a 99% confidence interval was desired to estimate the true proportion to within 5%?

Select one: A. 653 B. 690 C. 664 D. 611

Answer 1

Preliminary estimate for proportion (Known) = 0.5625
Margin of error =E=0.05
Level of significance =   0.01
Z critical value is (by using Z table) =2.576
Sample size formula is                   


=653.21  

A. 653