The similarities and relationship between Green’s Theorem and Stokes’ Theorem

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.

Worth 30 points! in this diagram, both polygons are regular. what is the value, in degrees, of the sum of the measures of angles abc and abd?

What is the radius of the cone in the diagram? round your answer to the nearest whole number