Lengths of pins (in mm) produced by a machine follow a N (mu, sigma 2) distribution. Find the maximum likelihood estimators of mu and sigma 2 based on a random sample of size 10 with observations: 7.12, 7.13, 7.01, 6.95, 6.89, 6.97, 6.99, 6.93, 7.05, 7.02.