We have two groups and we want to figure out the likelihood of being correct.
Are these two groups identical?
- 1. Calculate the difference in the means
- We use eqn 2.1 to calculate and and
- 2. Calculate the estimated variance of this difference
- We use eqn. 2.11 to do get
- 3. Form t
- 3. Calculate likelihood
- The number of degrees of freedom , is one less than the total number of data
points, that is it equals . With that and t, we feed it into a
program, or use a table to calculate the area under the curve as pictured in
- 4. Verdict
- If this area is less than our cutoff for significance, say we reject
and say the difference is statistically significant. Otherwise, we can't
- how to figure probability problems.