How do you find the variability of a sample?

Definition of Sample Variance
Step 1: Calculate the mean (the average weight).
Step 2: Subtract the mean and square the result.
Step 3: Work out the average of those differences
Info abt the formula: The variability of a data set as measured by the number R=xmax−xmin. The variability of sample data as measured by the number √Σ(x−ˉx)2n−1.

The second and fourth answer are correct