問題詳情

40. Figure [A] demonstrates a normal distribution of English midterm performance of Eagle class students. The statisticaldata shows that students’ mean score is 70 points, with a standard deviation of 10 points. There are 30 students inEagle class. Based on the data and the graph, which of the following statement is TRUE?


(A) w= 55, x=60, y=80, z=90
(B) Twenty-five students in Eagle Class scored above 60 and passed the English midterm exam.
(C) Students who scored within the 90-100 range were as many as students who scored within the 50-60 range.
(D) According to the graph, we are 95 percent certain that individual student’s actual score will be within one standarderror of 70 points.W X M Y Z 

參考答案

答案：B
難度：困難0.275862
統計：A(1),B(8),C(10),D(6),E(0)

用户評論

【Jessica】評論

above 60 60分以上依圖表了解60分以下約16%題幹中30 students in class30*16%=4.8 約530-5=25

【Moomin White】評論

 mean score is 70 points,  平均分數70分standard deviation of 10 points  標準差10分