You observe an investment that has the following historical returns:
	Year	Return
	1	27.66%
	2	0.90%
	3	21.81%
	4	14.17%
	5	15.33%
	6	9.14%
	7	-8.62%
	8	12.76%
	9	42.87%
	10	-12.67%
a.	What was the average (arithmetic mean) return over the 10 year period?
b.	What was the investment's variance over the 10 year period?