A colleague of yours is planning an experiment on the effect of a new diet they have developed for laboratory rats. They

[answerhappygod]

A colleague of yours is planning an experiment on the effect of
a new diet they have developed for laboratory rats. They want to
test the null hypothesis that mean body weight does not differ
between rats fed the new diet and rats fed an existing diet. They
are concerned that their test does not have enough statistical
power. Suggest three things that your colleague could do to improve
the statistical power of their test.