Express the Sum Using Summation Notation $\mathrm { n }$ , Where

Multiple Choice

Express the sum using summation notation. Use a lower limit of summation not necessarily 1 and k for the index of summation.
-The bar graph below shows a company's yearly profits from 1991 to 1999. Let an represent the company's profit, in millions, in year $\mathrm { n }$ , where $\mathrm { n } = 1$ corresponds to $1991 , \mathrm { n } = 2$ corresponds to 1992 , and so on.
Find $\sum _ { i = 3 } ^ { 7 } a _ { i }$

A) \$356.9 million
B) \$400.7 million
C) $\$ 142.6$ million
D) $\$ 371.3$ million