Frequency Table

Date: 09/17/2002 at 18:55:53
From: Brandon Dunbar
Subject: Frequency table

How do I make a frequency table using temperatures and days of the 
week? I put the days of the week in a row and then put the temperature 
for each day next to it, but it does not seem right to me. 

Thank you for your help.

Date: 09/18/2002 at 10:33:21
From: Doctor Ian
Subject: Re: Frequency table

Hi Brandon,

You're trying to relate three things, so this isn't going to be a 
typical frequency table, which would only relate two:

   Histogram
   http://mathforum.org/library/drmath/view/57612.html 

But you might try a different approach. Make a table with days of the 
week across the top and various temperatures down the side:

          S  M  T  W  T  F  S
  51-55
  56-60
  61-65
  66-70
  71-75
  76-80
  81-85
  86-90
  91-95
  96-100

Then whenever you get a certain temperature on a certain day, you can 
increment the count in the corresponding cell of the table. For 
example, if it's Tuesday, and it's 73 degrees, you'd have 

          S  M  T  W  T  F  S
  51-55
  56-60
  61-65
  66-70
  71-75         1
  76-80
  81-85
  86-90
  91-95
  96-100

The next time that happens, you'd increment it:

          S  M  T  W  T  F  S
  51-55
  56-60
  61-65
  66-70
  71-75         2
  76-80
  81-85
  86-90
  91-95
  96-100

The trick with something like this is to make it easy to spot 
patterns. For example, you might display the table using colors to 
indicate the number of hits in each cell - for example, 0 would be 
white, the maximum value for the table would be solid black, and 
various shades of gray would represent values in between. Or you could 
use different shapes to represent different ranges of frequencies 
(triangle for 0-10 hits, square for 11-20, pentagon for 21-30, and so 
on). 

I hope this helps. Write back if you'd like to talk more
about this, or anything else.

- Doctor Ian, The Math Forum
  http://mathforum.org/dr.math/