Students in an Econometrics class recorded their income, x, and the total amount of money they spent, y, for one week (in dollars.) Based on these data, the linear regression line was calculated as: y^=51.24+0.871x.

Jeffery conducted a survey in his school and found that 30 of the 50 eighth grade students' favorite subject is mathematics. based on the results, jeffery concluded that out of the 200 students in his school, 120 students' favorite subject is mathematics. select the statement that is true about jeffery's conclusion. a. jeffery's conclusion is not valid because the sample was biased since only 200 students were surveyed. b. jeffery's conclusion is valid because the sample was random since all of the students were eighth grade students. c. jeffery's conclusion is valid because the sample was random. d. jeffery's conclusion is not valid because the sample was biased since all of the students were eighth grade students.

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

2pointswhich of the following appear in the diagram below? check all that apply. d a. zcdeов. сеo c. aéo d. zdce