SOLUTION: I am having problems figuring out where to even start with the following, even just a hit would be appreciated. A survey of 200 university presidents was conducted, which 120 s

Algebra ->  Probability-and-statistics -> SOLUTION: I am having problems figuring out where to even start with the following, even just a hit would be appreciated. A survey of 200 university presidents was conducted, which 120 s      Log On


   



Question 909172: I am having problems figuring out where to even start with the following, even just a hit would be appreciated.
A survey of 200 university presidents was conducted, which 120 stated that their university
informally monitored social networking sites to stay on top of information related to their university.
a) Construct a 90% confidence interval for the proportion of universities that informally monitored social. Interpret the results.
b) If you want to conduct a follow-up study to estimate the population proportion of universities that informally monitored social networking sites to stay on top of information related to their university to within ±0.02 with 95% confidence, how many presidents would you survey?

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
a) ME = 1.645(sqrt( .6*.4/200) = .057
CI = .6 - ME < p < .6 + ME
CI =.543 < p < .657
b).02 = 1.96 (.6*.4/n)
n = .24/(.02/1.96)^2 = .24 / .0001 = 2400 Presidents