Question

For this problem, carry at least four digits after the decimal in your calculations. Answers may vary slightly due to rounding. In a survey of a random sample of 35 households in the Cherry Creek neighborhood of Denver, it was found that 14 households turned out the lights and pretended not to be home on Halloween. (a) Compute a 90% confidence interval for p, the proportion of all households in Cherry Creek that pretend not to be home on Halloween. (Round your answers to four decimal places.) lower limit upper limit

Answer 1

Let x be the number of households in Cherry Creek that pretend not to be home on Halloween.

x = 14

Sample size , n = 35

Sample proportion,  

We need to construct the 90% confidence interval for the population proportion.

The critical value for α=0.1 is z_{c ​}= z_1−α/2 ​= 1.645. The corresponding confidence interval is computed as shown below: