Question: Who tweets? Do younger people use Twitter more often than older people? In a random sample of 316 adult Internet users aged 18 to 29, 26% used Twitter. In a separate random sample of 532 adult Internet users aged 30 to 49, 14% used Twitter.
(a) Calculate the standard error of the sampling distribution of the difference in the sample proportions (younger adults - older adults). What information does this value provide?
(b) Construct and interpret a 90% confidence interval for the difference between the true proportions of adult Internet users in these age groups who use Twitter.