For the 33 nations in Example 7, we found a correlation of 0.682 between Internet use and

Question:

For the 33 nations in Example 7, we found a correlation of 0.682 between Internet use and Facebook use (both as percentages of population). The regression equation is predicted Facebook use = 3.09 + 0.460 Internet use
a. Based on the correlation value, the slope had to be positive. Why?
b. Indonesia had an Internet use of 10.5% and Facebook use of 13.49%. Find its predicted Facebook use based on the regression equation.
c. Find the residual for Indonesia. Interpret.