At the Annual 7th grade breakfast, the teachers buy the students a breakfast of bagels and juice. The table below shows the relationship between the number of students attending the breakfast and the total cost. If C=mS, where Cis the cost of S students and m is the constant of proportionality, what is the value of x? In June, the 7th grade teachers bought breakfast for150 students. What was the total cost? Show your work.