The mean absolute deviation of a set of data is the average distance between each data value and the mean. The mean number of contacts stored and the distance each data value is from the mean is shown below. Each data value is represented by an ×. So, the mean absolute deviation is 3.75<span>.
Polynomials can have double roots, in fact they're pretty common. if you get a reasonable zero it costs very little time to try it again for a double root. answer is the second choice
