Answer: (0.1118, 0.3454)
Step-by-step explanation:
Confidence interval for population proportion is given by :-
, where = sample proportion , n= sample size, = critical z-value for c confidence level.
Let p = the proportion of all households in Cherry Creek that pretend not to be home on Halloween.
Given : n= 35
Critical z-value for 90% confidence level =1.645
A 90% confidence interval for p, the proportion of all households in Cherry Creek that pretend not to be home on Halloween:
∴ Required confidence interval : (0.1118, 0.3454)