Answer:
90
Step-by-step explanation:
To find s4 we find sum of values when n=1,n=2,n=3,n=4
given expression is 
n=1 , plug in 1 for n

n=2

n=3

n=4

Sum of all 4 terms = 6+12+24+48=90
250 = 167.93 + x
[She needs $250, she has $167.93, and she needs x more. x represents the amount of money she still needs in order to get 250]
250 = 167.93 + x Subtract 167.93 on both sides
250 - 167.93 = 167.93 + x - 167.93
250 - 167.93 = x
82.07 = x
She needs $82.07 more
Or you could have done:
250 - 167.93 = 82.07
Answer:
-1, 12 I believe
Step-by-step explanation:
find the distance between the two given plots and do the opposite to find your answer
Formula for the sum of n terms of a finite arithmetic series is

If
then

Answer: 510.