Two sail boats are traveling along the same path away from a dock beginning from different locations at the same time. Johns boat begins 30 miles from the dock and is 50 miles from the dock after 5. hours the distance of Roberta's boat from the dock is represented by the function Y equals 5X +25 X represents time and Y represents the distance from the dock

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.

Having a hard time understanding this question (see attachment).

Will mark name all segments skew to bc