A survey by the Pew Research Center found that social networking is popular in many nations around the world. The file Global Social Media contains the level of social media networking (measured as the percent of individuals polled who use social networking sites) and the GDP per capita based on purchasing power parity (PPP) for each of 25 selected countries. (Data extracted from "Global Digital Communication: Texting, Social Networking Popular Worldwide," The Pew Research Center, updated February 29, 2012, p.5.)
a. Compute and interpret the coefficient of correlation, r.
b. At the 0.05 level of significance, is there a significant linear relationship between GDP and social media usage?
c. What conclusions can you reach about the relationship between GDP and social media usage?