Exercise 5.2: Split-Apply-Combine of the frog data set

---

We will continue working with the frog tongue adhesion data set.

You’ll now practice your split-apply-combine skills. First load in the data set. Then,

a) Compute standard deviation of the impact forces for each frog.

b) Compute the coefficient of variation of the impact forces and adhesive forces for each frog.

c) Compute a data frame that has the mean, median, standard deviation, and coefficient of variation of the impact forces and adhesive forces for each frog.

d) Now tidy this data frame. It might help to read the documentation about melting.