Question

Which of the following correctly uses the formula for the finite geometric series to derive the sum of the first seven terms of the geometric series 14 + 21 + 31.5 + 47.25 + . . . ?(1 point) Responses S7=14−14(1.5)61−1.5 upper S subscript 7 baseline equals Start Fraction 14 minus 14 left parenthesis 1.5 right parenthesis superscript 6 baseline over 1 minus 1.5 End Fraction S7=14−14(1.5)71+1.5 upper S subscript 7 baseline equals Start Fraction 14 minus 14 left parenthesis 1.5 right parenthesis superscript 7 baseline over 1 plus 1.5 End Fraction S7=14−14(1.5)71−1.5 upper S subscript 7 baseline equals Start Fraction 14 minus 14 left parenthesis 1.5 right parenthesis superscript 7 baseline over 1 minus 1.5 End Fraction S7=14−14(7)71−7

Answer 1

S7 = 14 - 14(1.5)7 / (1 - 1.5)