Question

Suppose that Student A's marks throughout the term had a mean of 78 with variance 16, and that Student B's marks throughout the term had a mean of 72 with variance 36. Which of the below statements is true?

(A) Student A had a higher average and Student B was more consistent. (B) Neither student had a higher average and Student B was more consistent. (C) Student A had a lower average and Student B was more consistent. (D) Student A had a lower average and was more consistent. (E) Student A had a higher average but neither student was more consistent. (F) Student A had a higher average and was more consistent. (G) Neither student had a higher average and Student A was more consistent. (H) Neither student had a higher average and neither student was more consistent. (I) Student A had a lower average but neither student was more consistent.

Answer 1

for student A, x= 78, 8²16 - 6=4 for student B, ý = 72, 82 36 36=6 Thus it is clear that student A had higher average. (78772) To See consistancy we calculate coefficient of variation for both students, Coefficient of variation (Cu) - Standard deviation xloo mean for student A, OVA = Kloo C.VA = 5.13% me lone for student B, C.UB= a x100 8.33%

C.VA< C.V.B. The student with consistant less c.v. is more & student A is more consistant. True statement is (F) and student A had a higher average was more consistent-