Express the Sum Using Summation Notation $$3 + 6 + 9 + \ldots + 21$$

question 73

Multiple Choice

Express the sum using summation notation. Use 1 as the lower limit of summation and i for the index of summation.
- $$3 + 6 + 9 + \ldots + 21$$

• A) \(\sum _ { i = 1 } ^ { 7 } 3 i ^ { 2 }\)
• B) \(\sum _ { i = 1 } ^ { 7 } i ^ { 2 }\)
• C) \(\sum _ { i = 1 } ^ { 7 } 3 i\)
• D) \(\sum _ { i = 0 } ^ { 7 } 3 i\)

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