Use the following information to answer the question.
Researchers at the University of Mississippi wanted to determine whether the reaction time (in seconds) to go/no go stimulus of males differed from that of females. The researchers randomly selected 20 females and 15 males to participate. The go/no go stimulus required the student to respond to a particular stimulus and not to respond to other stimuli. The researchers decided to construct a confidence interval to determine if the difference of the means is significant.
What would they need to check to make sure that the requirements are satisfied?