Maths. F.3
回答 (7)
2007-01-04 2:28 am
✔ 最佳答案
首先要判斷x係o係邊個位52,60,70,83,100
如果係細過60, 咁個median就會係(60+70)/2=65
如果係大過83, 咁個median就會係(70+83)/2=76.5
而家個median係72.5, 即係x應該o係70既左或右一個位
median=(70+x)/2=72.5
x=75
做數先要理解問題, 再適當既方法或者式
2007-01-04 2:21 am
先重組data,有小至大52,60,70,83,100, 我們要估計x的位置,
可能性
1.如果x放在52和60中間或52之前,median 是(60+70)/2,不等如72.5
2.如果x放在83和100中間或100之後,median 是(70+83)/2,不等如72.5
所要只有第3個可能性,就是在60和70中間或70和83中間,兩個可能性的計法都是(x+70)/2=72.5, x+70=145, x=75,x在70和83中間
可能性
1.如果x放在52和60中間或52之前,median 是(60+70)/2,不等如72.5
2.如果x放在83和100中間或100之後,median 是(70+83)/2,不等如72.5
所要只有第3個可能性,就是在60和70中間或70和83中間,兩個可能性的計法都是(x+70)/2=72.5, x+70=145, x=75,x在70和83中間
2007-01-04 2:18 am
List the number like that :52,60,70,83,100,x
the median is the mean of the middle two data
the median is larger than 70
so x is the forth number(第4個數)
(x+70)/2=72.5
x+70=145
x=75
the median is the mean of the middle two data
the median is larger than 70
so x is the forth number(第4個數)
(x+70)/2=72.5
x+70=145
x=75
2007-01-04 2:16 am
x = 75
the scores have to be :
52, 60, 70, 75, 83, 100 for the median to be equal to 72.5.
X has to be the middle of 70 and a number between 83 & 70. therefore:
(70 + x)/2 = 72.5
x=75
the scores have to be :
52, 60, 70, 75, 83, 100 for the median to be equal to 72.5.
X has to be the middle of 70 and a number between 83 & 70. therefore:
(70 + x)/2 = 72.5
x=75
2007-01-04 2:14 am
∵median=72.5
∴(83+100+52+70+60+x)/6=72.5
365+x=72.5*6
365+x=435
X=70
∴(83+100+52+70+60+x)/6=72.5
365+x=72.5*6
365+x=435
X=70
2007-01-04 2:12 am
83+100+52+70+60+x
-------------------------------- = 72.5
6
x=72.5x6-100-83-52-70-60
=70
-------------------------------- = 72.5
6
x=72.5x6-100-83-52-70-60
=70
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