问题求解，题目看起来简单，可是不明白具体意思。。。 highest

c8143

Question 27


Twenty students take an exam. The percentages of questions they answer correctly are ranked from lowest to highest as follows:

32	49	57	58	61
62	64	66	67	67
68	69	71	72	72
74	76	80	82	83

In a frequency distribution from 30% to 90% that is divided into six equal-sized intervals, the absolute frequency of the sixth interval is:

A) 2.

B) 4.

C) 1.

D) 3.


有个帖子给的答案是 D，我不明白，求解！