1. The ages of a group people are listed in an increasing order as 13, 15, 16, 17, 19, 20, 20, 21, 22, 23, 25, 25, 26, 30, 31, 32, 35, 35, 35, 36, 48, 50, 52, 55, 70. (a) Use clustering to smooth these data, the number of clusters is 3. Illustrate your steps. Comment on the effect of this technique for the given data. (b) How might you determine outliers in the data? (c) What other methods are there for data smoothing?