I'm trying to trying to work out the mean average age based on the data from a survey when the ages are ranged. The ages are ranged 16 - 21, 22 - 26, 27 - 32 etc.
So for example 4 respondents where aged between 16-21, 7 between 22-26 and 12 between 27-32.
Does anyone know how to do this? I know how to work out the mean, but how do you do it when the data is presented like this?
Thanks!
2007-09-04 05:45:35 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Unfortunately you can not get the exact average. However you can obtain an estimate by using the middle value of each range.
16-21 -> 18.5
22-26 -> 24
27-32 -> 29.5
(18.5*4 + 24*7 + 29.5*12)/(4+7+12) = 25.91
I think this method works ok, espcially if there are large numbers of people involved
2007-09-04 05:58:13 · answer #1 · answered by Mike 5 · 0⤊ 0⤋
2
2016-07-24 00:32:39 · answer #2 · answered by ? 3 · 0⤊ 0⤋
You can get an approximation, but not an exact mean. To get an exact number, you would have to know the distribution within each range.
But to approximate, multiply the number in each range with the median age in the range then divide by the total:
(4*18.5 + 7*24 + 12*29.5 + ...)/(4 + 7 + 12 + ...)
2007-09-04 05:55:53 · answer #3 · answered by gebobs 6 · 0⤊ 0⤋
Xbar = [Σ(fi)(xi)]/n
Where fi is the frequency of the ith group and xi is the mid-point of the ith group. Add all the i products and divide by the total number of values.
2007-09-04 06:05:34 · answer #4 · answered by cvandy2 6 · 0⤊ 0⤋
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2016-07-06 14:02:42 · answer #5 · answered by ? 3 · 0⤊ 0⤋