单选题 Given the following frequency distribution:
Interval
Frequency
10 up to 30
5
30 up to 50
10
50 up to 70
15
70 up to 90
5
Which of the following statements is FALSE?
  • A. The interval size is 20.
  • B. The relative interval frequency of the second interval is 14.28.
  • C. The interval frequency of the third interval is 15.
【正确答案】 B
【答案解析】The relative interval frequency is ( interval frequency)/( total number) = 28.57.