From about 1996 to 2000, vegetation was taken out around the lakeshore to make it look more ...

     From about 1996 to   2000, vegetation was taken out around the lakeshore to make it look more   cosmetically pleasing. The water quality quickly declined due to increased   nutrient flow into the lake, making the lake unhealthy. Around 2000, the   vegetation removal and cutting of the grass down to the shoreline stopped,   and more trees were planted. Lake Pamela’s TSI (trophic state index) data is   given in the table below (the maximum value for each year is used). The TSI   of a lake measures the biological condition of the lake, or how healthy it   is. Generally speaking, the lower the TSI, the healthier a lake is.   Years since 2002, x      TSI, y=f(x)   0                                 45.2   2                                 47.1   4                                 41   6                                 44.6   8                                 42.5   10                               37.6      1) Is TSI (y) a function of years (x)?   How do you know this?   2) While the data does not form a single   straight line, the shape of the data suggests a linear pattern. Pick any two   data points so that when a straight line is drawn through those two points,   it is a line that best fits the data. Draw your line of best-fit through your   two chosen data points on the graph. Then, state your two chosen data points,   as ordered pairs, below. (Hint: Your two points may be found through trial   and error. Draw a straight line connecting any two data points and see if the   line is a good approximation for the data; if not, try two other data points.   They do NOT have to be consecutive data points.)