(a) The median of the data set x,37,48 and 19 is 30. Find the value of x.Hence find the mean of these four numbers.
ANS : x = 23,mean = 31.75
(b)If a number y is added to the data set in part (a),the median remains uncharged. Find the value of y and the mean of these five numbers.
ANS : y = 30,mean = 31.4
(c)If another y is added to the set of five numbers in part (b),will the median and the mean charge?Why?
ANS : The median will not change,but the mean will charge.
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2011-01-10 9:37 am
回答 (2)
2011-01-10 10:54 am
✔ 最佳答案
a)The data set is (19 , x , 37 , 48)(x + 37)/2 = 30x = 23mean = (19 + 23 + 37 + 48)/4 = 31.75b)The data set must be (19 , 23 , y , 37 , 48) otherwise the median will not be
30.So the median = y = 30The mean = (19 + 23 + 30 + 37 + 48)/5 = 31.4
c)The data set must be (19 , 23 , y , y , 37 , 48)The median = (y + y)/2 = y = 30 remain unchange ,
but the mean will change (decrease) since y = 30 is less then the old mean 31.4.
2011-01-11 12:10 am
(a)19,x,37,48
madian=(x+37)/2=30
=23
mean=(19+23+37+48)/4
=31.75
(b)because median remain unchange,so y must be30
mean=(19+23+30+37+48)/5
=31.4
(c)median(19,23,30,30,37,48)=(30+30)/2=30
mean=(19+23+30+30+37+48)/5
=31.4
so the median and the mean remain unchange
2011-01-10 16:14:21 補充：
呢個先至正確
(a)19,x,37,48
madian=(x+37)/2=30
=23
mean=(19+23+37+48)/4
=31.75
(b)because median remain unchange,so y must be30
mean=(19+23+30+37+48)/5
=31.4
(c)median(19,23,30,30,37,48)=(30+30)/2=30
mean=(19+23+30+30+37+48)/5
=37.4
so the median remain unchange and the mean is change
madian=(x+37)/2=30
=23
mean=(19+23+37+48)/4
=31.75
(b)because median remain unchange,so y must be30
mean=(19+23+30+37+48)/5
=31.4
(c)median(19,23,30,30,37,48)=(30+30)/2=30
mean=(19+23+30+30+37+48)/5
=31.4
so the median and the mean remain unchange
2011-01-10 16:14:21 補充：
呢個先至正確
(a)19,x,37,48
madian=(x+37)/2=30
=23
mean=(19+23+37+48)/4
=31.75
(b)because median remain unchange,so y must be30
mean=(19+23+30+37+48)/5
=31.4
(c)median(19,23,30,30,37,48)=(30+30)/2=30
mean=(19+23+30+30+37+48)/5
=37.4
so the median remain unchange and the mean is change
收錄日期: 2021-04-13 17:47:56
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110110000051KK00101