Question

In the week before and the week after a holiday there were 10,000 total deaths and 4968 of them occurred in the week before the holiday.
a) construct a 90% confidence interval estimate of the proportion of deaths in the week before the holiday to the total death in the week before and the week after the holiday

b) based on the result does there appear to be any indication that people can temporarily postpone their death to survive the holiday

Answer 1

THIS MAY HELP YOU

CI = mean proportion ± (z*)sqrt[ (p)(1-p) / n]
where z* = 1.645 with 10%/2 = 0.05 area in each tail mean proportion p = 4946 / 10000 = 0.4946 now fill in the values from the problem ...
 CI = mean proportion ± (z*)sqrt[ (p)(1-p) / n]
 CI = 0.4946 ± (1.645)sqrt[ (0.4946)(1- 0.4946) / 10000]
 CI = (0.4864, 0.5028)