Given the formula, Sn=a 1-r^n/1-r, what is the sum of the first nine terms of the geometric series: 324, - 108, 36, - 12 ...

If necessary, round to the hundredths place. (2 places after the decimal)

Question

Moonshine

Mathematics

21 June, 18:57

Given the formula, Sn=a 1-r^n/1-r, what is the sum of the first nine terms of the geometric series: 324, - 108, 36, - 12 ...

If necessary, round to the hundredths place. (2 places after the decimal)

+2

Answers (1)

Know the Answer?

Hezekiah Kelly · Answer 1

243.01.

Step-by-step explanation:

The first term (a) = 324.

The common ratio (r) = - 108/324 = - 1/3.

So sum of 9 terms is:

S (9) = 324 * (1 - (-1/3) ^9) / (1 - (-1/3)

= 324 (1 - (-0.00005076)) / 4/3

= 324 * 1.00005076 / 1.33333

= 243.012.

Given the formula, Sn=a 1-r^n/1-r, what is the sum of the first nine terms of the geometric series: 324, - 108, 36, - 12 ...If necessary, round to the hundredths place. (2 places after the decimal)

Given the formula, Sn=a 1-r^n/1-r, what is the sum of the first nine terms of the geometric series: 324, - 108, 36, - 12 ...

If necessary, round to the hundredths place. (2 places after the decimal)