Step 1
Obtain your 20 data points (10 initial mass and 10 final mass)
Step 2
For each final and initial mass find the % change (final-initial/initial)
Step 3
In Excel enter your 5 % change values for water and 5 % change values for other
Step 4
Ask Excel to calculate MEAN by clicking fx
and choosing AVERAGE. It will prompt you to identify the
range of values that you want to choose to calculate the
mean from. Repeat for each treatment (water v other).
Step 5
Same procedure but ask Excel to calculate
the STDEVA for each data group. You will have five points of
data that you are highlighting for each calculation. Repeat
for each treatment (water v other)
Step 6
Highlight your two MEANS and labels. On
your iPad you will choose “Insert” and “Chart”. Choose column and
click the first column illustration that it gives to you.
Step 7
Manually add error bars that represent your SD values
for each treatment. For example: If my SD is 2 I would draw an error
bar that extends 2% above and below my mean.
Step 8
Go to the link for the t-test calculator. Enter your 5 %
change values for treatment 1 (water), 5 % change values for
treatment 2 (other). Scroll to the bottom of the page and IN BLUE it
will tell you the results of your t-test.