Important risk factors for high blood pressure reported by the National Institute of Health include weight and ethnicity. High blood pressure is common in adults who are overweight and are African American. a public policy researcher in Atlanta surveyed 150 adult men about 5′10″ in height and in the 55–60 age group. Data were collected on their systolic pressure, weight (in pounds), and race (Black = 1 for African American, 0 otherwise). The resulting regression equation which includes the interaction between weight and race is: Systolic = 70.8312 + 0.4362Weight + 30.2482Black − 0.1118(Weight × Black). The interaction variable is negative and statistically significant at the 5% level. Interpret what a negative interaction implies in this example:

5\16 x 2\5 = 10/80simplify to 1/80

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )

The key is the word about, they want an estimation.63 is closer to 60, 71 is closer to 7060 + 70 = 130ryan counted about 130 birds