Shalit Corporation's 2001 sales were $12 million. Sales were $6 million 5 years earlier (in 1996).

a. To the nearest percentage point, at what rate have sales been growing?

b. Suppose someone calculated the sales growth for Shalit Corporation in part a as follows:

"Sales doubled in 5 years. This represents a growth of 100 percent in 5 years, so, dividing 100 percent by 5, we find

the growth rate to be 20 percent per year." Explain what is wrong with this calculation.