15. Quartiles divide a sample into four nearly equal pieces. In general, a sample of size n can be broken into k nearly equal pieces by using the cutpoints(i/k)(n+1) for i = 1,..., k − 1. Consider the following ordered sample: 2 18 23 41 44 46 49 61 62 74 76 79 82 89 92 95

a. Tertiles divide a sample into thirds. Find the tertiles of this sample.

b. Quintiles divide a sample into fifths. Find the quintiles of this sample.