Question

The Borat Cultural Learnings of America Research Institute conducted a survey of 1000 randomly sampled college students in the United States and asked them if they have an Android smartphone. 434 of the 1000 students indicated they own an Android smartphone. Obtain a 95% confidence interval for the proportion of college students in the United States that own an Android smartphone.

Answer 1

Solution:

Given in the question

Sample proportion = 434/1000 = 0.434

95% confidence interval is

P+/- Zalpha/2*Sqrt(p*(1-p)/n)

0.434+/-1.96*Sqrt(0.434*(1-0.434)/1000)

0.434+/- 1.96*0.0158

0.434+/-0.0307

So 95% confidence interval is

0.403 to 0.465