, , , , ,

This is the formula to find the sum of the first terms of the sequence. To evaluate it, the values of the first and th terms must be found.

This is an arithmetic sequence since there is a common difference between each term. In this case, adding to the previous term in the sequence gives the next term. In other words, .

Arithmetic Sequence:

This is the formula of an arithmetic sequence.

Substitute in the values of and .

Apply the distributive property.

Multiply by .

Subtract from .

Substitute in the value of to find the th term.

Multiply by .

Add and .

Replace the variables with the known values to find .

Divide by .

Add and .

Multiply by .

Convert the fraction to a decimal.

Find the Sum of the Series 3 , 5 , 7 , 9 , 11 , 13