Suppose you conduct a poll if people like some product or like some TV-show.
Assign your numbers for total number of people you asked (n - sample size), numbers of people who answered "yes" to the given question (n1), calculate sample proportion p = n1/n and then
calculate confidence interval for population proportion.
Apply confidence level 95% (z c = 1.960).
The solution provides step by step method for the calculation of confidence interval for population proportion. Formula for the calculation and Interpretations of the results are also included. Interactive excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.