题目
An investment fund has the return frequency distribution shown in the following exhibit.「huixue_img/importSubject/1564548693946929152.png」Which of the following statements is correct?
选项
A.The relative frequency of the bin “-1.0 to +2.0” is 20%.
B.The relative frequency of the bin “+2.0 to +5.0” is 23%.
C.The cumulative relative frequency of the bin “+5.0 to +8.0” is 91.7%.
答案
A
解析
A is correct. The relative frequency is the absolute frequency of each bindivided by the total number of observations. Here, the relative frequency is calculatedas: (12/60) × 100 = 20%. B is incorrect because the relative frequency ofthis bin is (23/60) × 100 = 38.33%. C is incorrect because the cumulative relativefrequency of the last bin must equal 100%. A是正确的。相对频率，指的是落在某一个区间中数据的占比，即每个区间中的绝对频数除以观测总数。此处，相对频率计算为：（12/60）×100=20%。 B是不正确的，这个区间的相对频率为（23/60）×100=38.33%。 C是不正确的，最后一个区间的累积相对频率必须等于100%。