Elementary Statistics
posted by Erin on .
1) Construct a confidence interval of the population proportion at the given level of confidence.
x=60,n=300, 99% confidence.
The 99% confidence interval is (_,_)
2) A researcher wishes to estimate the proportion of adults who have highspeed internet access. What size sample should be obtained if she wishes the estimate to be within 0.04 with 99% confidence if
a) she uses a previous estimate of 0.52?
b) she does not use any prior estimates?

1. 99% = mean ± 2.575 SEm
SEm = SD/√n
What is the value of the standard deviation (SD)?