In: Statistics and Probability
Question 2: Correct to three decimal places if necessary.
(1) 200 Hong Kong drivers were randomly sampled and it was
discovered that 25 of these drivers were illegally
talking on the cell phone without the use of a hands-free device.
Find the point estimator for the proportion
of drivers who are using their cell phones illegally and construct
a 95% condence interval.
(2) America's young people are heavy Internet users: 87% of
Americans ages 12 to 17 are Internet users. MySpace
was voted the most popular website by 9% in a sample survey of
Internet users in this age group. Suppose
1400 youths participated in the survey. What is the margin of error
and what is the interval estimate of the
population proportion for which MySpace is the most popular
Website? Use a 95% condence level.