math
posted by jeng .
Consider the following method of estimating
Fahrenheit temperatures given Celsius temperatures
(which was stated earlier in this section):
To estimate the Fahrenheit temperature for a given Celsius
temperature, double the Celsius temperature and add 30.
Create a spreadsheet comparing the estimates with the
actual Fahrenheit temperatures for Celsius temperatures
from 0 to 40°. (The estimate can be expressed as follows:F = 2C + 30
.) For what temperatures is the estimate
most accurate? least accurate? Are there any Celsius temperatures
for which the estimate is exactly correct?

In Excel, I would create 3 columns
Put 0 into A1
in B1 type: A1*2 + 30
in C1 type : A1*(9/5) + 32
in A2 type : =A1 + 1
select A2 to A101, "fill down"
"fill down" the values for columns B and C from 1 to 101
as a check: my values for 20 are 70 and 68
and at 10º F I get 50 in both columns