A recent study of 750 internet users in Europe found that 35% of internet users were women. What is the 95% confidence interval of the true proportion of women in Europe who use the internet? D)

Question

Quizplus · Accepted Answer

We can use the formula for the confidence interval of a proportion:

CI = p ± z*sqrt[p(1-p)/n]

where:
p = sample proportion = 0.35
n = sample size = 750
z = z-score for 95% confidence level = 1.96 (from standard normal distribution)

Plugging in the values:

CI = 0.35 ± 1.96*sqrt[0.35(1-0.35)/750]
CI = 0.35 ± 0.032
CI = (0.318, 0.382)

Therefore, the 95% confidence interval for the true proportion of women in Europe who use the internet is (0.318, 0.382). Choice C is the only one that matches this interval.

A Recent Study of 750 Internet Users in Europe Found