The following are the marks secored by 40 students in an examination.
26 30 34 44 44 45 46 46 48 51
52 55 56 57 58 60 60 60 66 66
66 67 67 72 72 72 73 76 78 78
82 83 83 83 85 87 89 89 90 92
a)construct a frequency distribution table with class intervals 20-29,30-39,and so on for the given data,
b)From the frquency distribution table in a) ,
(1)find the mean mark correct to 1 decimal place,
(2)construct a cumulative frequency polygon,
(3)find the 75th percentile of the marks
數學題...你一定要幫拖!!!
2007-01-30 1:57 am
回答 (3)
2007-01-30 3:17 am
✔ 最佳答案
part a, 畫圖, 20-29 有1 個, 30-39 有 2 個, 40-49 有6 個, 50-59 有 6 個, 60-69 有8 個, 70-79 有 7 個, 80-89 有8個, 90-99 有2個part b , 1, (40+1)/2=20.5 第20.5是個中位數,所以個中位數是= (66+66)/2 = 66
2, 唔是好明問咩...我估是問邊個數出現最多,咁就應該是60, 66, 72,83
3, 40x3/4= 30第30個位是78 ,78is the 75th percentile of the marks
2007-01-30 2:01 am
你好畫圖....有排畫
收錄日期: 2021-04-12 21:30:44
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