Warm Up A 2010 study looked for an association between median SAT scores and 6 year graduation rates at 10 colleges. College SAT Grad rate College SAT Grad rate 1 1160 81.2 6 1030 48.9 2 1135 64.9 7 1010 46.5 3 1015 61.2 8 950 42.9 4 1040 52.7 9 990 38.8 5 975 50.5 10 905 31.3 1) Find the equation of the LSRL and the value of r. 2) Interpret the slope in context. 3) Predict the graduation rate for a school with median SAT of 1100.

Guess the Graduation Rate College SAT Grad rate College SAT Grad rate 1 1160 81.2 6 1030 48.9 2 1135 64.9 7 1010 46.5 3 1015 61.2 8 950 42.9 4 1040 52.7 9 990 38.8 5 975 50.5 10 905 31.3 For SAT: Mean = 1021 Std Dev = 77.8 For Grad Rate: Mean = 51.9. Std Dev = 14.3 1) If a college is chosen at random, what would you predict its grad rate to be? How far off from the correct value would you expect to be? 2) If a college is chosen at random and you are told the SAT score is 1100, predict the grad rate and error again.

Practice A method to estimate the age of a lobster was investigated in a 2007 study. The length of the exterior shell was compared to the known age of 10 lobsters. The data is below. Lobster Length Age Lobster Length Age 1 63.32 1.0 6 79.32 1.42 2 110.64 2.18 7 133.95 2.50 3 105.07 1.82 8 145.78 3.42 4 152.04 4.08 9 118.99 2.17 5 152.73 3.41 10 123.51 2.50 1) Find the equation of the LSRL and r. 2) Find r2 and interpret its meaning.