Hello all,
Slightly confused here. I have the following data:
Less than 5 minutes 7,990
5 to 9 minutes 30,778
10 to 14 minutes 48,575
15 to 19 minutes 65,983
20 to 24 minutes 69,709
25 to 29 minutes 28,965
30 to 34 minutes 72,458
35 to 39 minutes 12,896
40 to 44 minutes 14,116
45 to 59 minutes 32,932
60 to 89 minutes 14,506
90 or more minutes 8,366

which I would like to calculate a Median for...is this possible?
Thanks,
Larry

Larry,
Is this what you are looking for?
Type in Median into help and select the first option and you should see
this.

Calculate the median of a group of numbers
Use the MEDIAN function to do this task. The median is the value at the
center of an ordered range of numbers.


A
Data
10
7
9
27
0
4
Formula Description (Result)
=MEDIAN(A2:A7) Median of numbers in list above (8)

HTH


--
Casey


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Larry Holt -

Since your data are already grouped, the best you can do is make an
assumption about the distribution and then estimate the median.

The median is the "middle-ranked value." Approximately half of the values
are below the median, and approximately half are above.

The first step is to put all observations in rank order. In your case, the
observations are in ranked intervals.

The second step is to find the middle rank. Add up 7990+ 30778+...+8366, and
divide by 2. (Middle rank is 203,637.)

The third step is to find the interval containing the middle rank.
Accumulate 7990+ 30778+... until you identify that interval. (Interval 20 to
24 minutes has ranks 153,327 through 223,035.)

The fourth step is to make the assumption that the values in that middle
interval are uniformly distributed. (Assuming the measurements are to the
nearest minute, the five distinct values in the middle interval are 20, 21,
22, 23, and 24, each with approximately 13,942 values, i.e., 69,709 divided
by 5.)

The fifth step is to determine which of the five values is associated with
the middle rank. (Value 20 has ranks 153,327 through 167,268; value 21 has
ranks 167,269 through 181,210; value 22 has ranks 181,211 through 195,152;
value 23 has ranks 195,153 through 209,094, which includes the middle rank,
203,637. So the median is 23 minutes.)

Other interpolation schemes are possible. Here I assumed the original values
are discrete (integer-valued minutes) instead of continuous.

- Mike
http://www.mikemiddleton.com

"Larry Holt" wrote in message
...
Hello all,
Slightly confused here. I have the following data:
Less than 5 minutes 7,990
5 to 9 minutes 30,778
10 to 14 minutes 48,575
15 to 19 minutes 65,983
20 to 24 minutes 69,709
25 to 29 minutes 28,965
30 to 34 minutes 72,458
35 to 39 minutes 12,896
40 to 44 minutes 14,116
45 to 59 minutes 32,932
60 to 89 minutes 14,506
90 or more minutes 8,366

which I would like to calculate a Median for...is this possible?
Thanks,
Larry

Mike Middleton wrote:
Other interpolation schemes are possible. Here I assumed the
original values
are discrete (integer-valued minutes) instead of continuous.


painful :)
but thanks for taking the time to explain all that to me, I can use it
on the 1990 data now!
Larry