The number of banks in a country has been dropping steadily since 1984, and the trend in recent years has been roughly linear. The annual data for the years 1999 through 2008 can be summarized as follows, where x represents the years since 2000 and y the number of banks, in thousands. n equals=10. ∑x equals=235. ∑x^2 equals=5605. ∑y equals=77.564. ∑y^2 equals=603.80424. ∑xy equals=1810.155 a. Find an equation for the least squares line.
b. Use your result from part a to predict the number of banks in the year 2020.
c. If this trend continues linearly, in what year will the number of banks drop below 6200?
d. Find and interpret the correlation coefficient.