Answer:
any number except -20
Step-by-step explanation:




Multiply by -1 to make the k positive. This will alter all the terms which means 20 will become negative. NOTE: When multiplying or dividing by negative numbers, the inequaliy sign flips.

k must be either greater than -20 but not including it or fewer than -20 but not including it; therefore, any number between negative infinity and -21 and -19 and postive infinity
Hello,
Please, see the attached file.
Thanks.
<h3>
Answer: 78.6</h3>
Work Shown:

Multiply across the rows to form a third column. Example: 9*90 = 810 in the first row.

The values in the third column add to 810+1440+1050 = 3300
Divide this over the total number of people which is 9+18+15 = 42
The mean is 3300/42 =78.571 approximately which rounds to 78.6
-4 I believe I’m not sure tho

The formula of the sum of a geometric sequence:

We have:

substitute:

Answer: C. -5460