Why do we square the residuals when using the least-squares line method to find the line of best fit? a.) Squaring the residuals makes it easier to identify smaller residuals. b.) It amplifies the effect of having negative and positive residuals. c.) It cancels out the effect of having negative and positive residuals. d.) We don't square the residuals when using the least-square method.

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z