The value of the final deposit is 5000. The value of the one a year previously is 5000*1.1 = 5500. The one previous to that has a value of 5000*1.1^2 = 6050. The first deposit has a value of 5000*1.1^3 = 6655.
The total value of the 4 deposits is
.. 6665 +6050 +5500 +5000 = 23,205
You will have $23,205 just after you make the 4th deposit.
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This is the sum of 4 terms of a geometric sequence with common ratio 1.1 and initial value 5000. That can be calculated as
.. a0*(r^n -1)/(r -1)
.. 5000*(1.1^4 -1)/(1.1 -1)
.. = 5000*4.641
.. = 23,205
I think it’s a cause if just divide and multiply
Yes scale factor means ratio. The height of the smaller pyramid to the larger pyramid in ratio form is 8:24 which simplifies to 1:3. The ratio of its areas is the scale factor squared, so 1^2:3^2=1:9. Since the surface area of the smaller pyramid is 124, the surface area of the larger pyramid must be 124x9. The ratio of volumes is the scale factor cubed, so 1^3:3^3=1:27. If the volume of the larger pyramid is 648, then the volume of the smaller pyramid is 1/27 of that, which equals 24.
