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.⁷Hampton, K.,Goulet, L.,Rainie, L., andPurcell, K., "Social Networking Sites and Our Lives,"Pew Research Center, June 16,2011. Find and interpret a

99% confidence interval for each of the following proportions:

Proportion of US adults who use the Internet regularly.

(b)

Proportion of US adult Internet users who use a social networking site.

(c)

Proportion of all US adults who use a social networking site. Use the confidence interval to estimate whether it is plausible that 50% of all US adults use a social networking site.