In a survey of 2255 randomly selected US adults (age 18 or older), 1787 of them use the Internet regularly.
Of the Internet users, 1054 use a social networking site.1Find a 90%
confidence interval for each of the following proportions.
(a) Proportion of US adults who use the Internet regularly.
The 90% confidence interval is ____to ___
(b) Proportion of US adult Internet users who use a social networking site.
The 90 confidence interval is ___ to ____
(c) Proportion of all US adults who use a social networking site.
The 90% confidence interval is ____ to ____
Use the confidence interval to estimate whether it is plausible to estimate that 50%
of all US adults now use a social networking site.