I'm guessing S^20 is actually referring to the 20th partial sum

, with

in the arithmetic case, and

in the geometric case.
(a) Combining like terms, we have

and invoking the formula

we end up with

(b) Multiply

by 1.1, then subtract this from

:


Answer:
c
Step-by-step explanation:

pls mark brainliest
The outlier in the data set is 5
Answer:
possible values of 4th term is 80 & - 80
Step-by-step explanation:
The general term of a geometric series is given by

Where a(n) is the nth term, r is the common ratio (a term divided by the term before it) and n is the number of term
- Given, 5th term is 40, we can write:

- Given, 7th term is 10, we can write:

We can solve for a in the first equation as:

<em>Now we can plug this into a of the 2nd equation:</em>
<em>
</em>
<em />
<em>Let's solve for a:</em>
<em>
</em>
<em />
Now, using the general formula of a term, we know that 4th term is:
4th term = ar^3
<u>Plugging in a = 640 and r = 1/2 and -1/2 respectively, we get 2 possible values of 4th term as:</u>

possible values of 4th term is 80 & - 80
4 dollars flat $4.00
Step-by-step explanation:
1.25x4= 5$ 5$+5$=10$