Answer
Interaction P-value $=0.985$. Do not reject the null hypothesis.
There is not enough evidence to conclude that there is an interaction between Age and Stimulus.
Work Step by Step
$H_0:$ there is no interaction between Age and Stimulus.
versus
$H_1:$ there is an interaction between Age and Stimulus.
In MINITAB 18, enter the data according to the table below.
Select Stat -> ANOVA -> General Linear Model -> Fit General Linear Model
In Responses enter Reaction Time (C3). In Factors enter Age Stimulus (C1 C2).
Click Model. In Factors and covariates highlight both Age and Stimulus. Click Add (to the right of Interactions through order). Age*Stimulus will appear in 'Terms in the model'. Click OK.
Click Ok.
The interaction P-value $=0.985$
