Create an array called differences that is the difference between the petal lengths (versicolor_petal_length) and the mean petal length. The variable versicolor_petal_length is already in your namespace as a NumPy array so you can take advantage of NumPy's vectorized operations.
Square each element in this array. For example, x**2 squares each element in the array x. Store the result as diff_sq.
Compute the mean of the elements in diff_sq using np.mean(). Store the result as variance_explicit.
Compute the variance of versicolor_petal_length using np.var(). Store the result as variance_np.
Print both variance_explicit and variance_np in one print call to make sure they are consistent.

Introduction to summary statistics: The sample mean and median