The Calculation of Confidence Interval

The sale manager for a hardwarewholesaler finds that 229 of the previous 500 calls to the hardware store owners resulted in new product placements. Assume these 500 calls represent a random sample.
a. What is the upper confidence limit of a 95% confidence intervalfor the population proportion of new product placements?
b. What is the lower confidence limit of a 95% confidence interval for the population proportion of new product placements.
c. What level of confidence is associated with an interval of .400513 to .515487 for the population proportion of new product placements?

Answers
a. Upper confidence limit = 0.414328765
b. Lower confidence limit = 0.501671235
c. …

The solution provides step by step method for the calculation of confidence interval.