PP-PS-T1-118

[whoisallan]

ps1-118. 12240-!-item-!-187;#058&008164
For a certain examination, a score of 58 was 2 standard deviations below the mean, and a score of 98 was 3 standard deviations above the mean. What was the mean score for the examination?

(A) 74
(B) 76
(C) 78
(D) 80
(E) 82

ANS:(A)

請問如何下手?

[Huang Hsin-Yi]

設mean=M, standard deviation=S

(1)M-2S=58
(2)M+3S=98

解聯立