Answer:
The correct option is;
C) 6554
Step-by-step explanation:
The given data are;
Day, Amount of change in Bacteria
1, 2
2, -8
3, 32
4, -128
Given that the data follows a geometric sequence, we have;
The first term of the series = 2, the common ratio = -4, the sum of a geometric progression is given by the following formula;
[tex]S_n = \dfrac{a \times \left (r^n - 1\right )}{r - 1}[/tex]
Which gives;
[tex]S_7 = \dfrac{2 \times \left ((-4)^7 - 1\right )}{(-4) - 1} = \dfrac{2 \times \left (-16384- 1\right )}{-4 - 1} = \dfrac{2 \times \left (-16385\right )}{-5} = 6554[/tex]
Therefore, the correct option is C) 6554.
