A medical researcher wanted to determine the effect of pH (a measure of alkalinity or acidity, with pure water having a pH of 7) on the growth of a bacteria culture. The table below gives the measurements of different cultures, in thousands of bacteria, after 8 hours.
pH Number of bacteria
(a) Find the linear regression equation for these data. (Round your coefficients to three decimal places. A graphing calculator is recommended.)
(b) Using the regression model, what is the expected number of bacteria when the pH is 6.5? Round to the nearest thousand bacteria.