21 and 22 because 21+22=43
Answer:
Step-by-step explanation:
The standard deviation is the square root of the variance, and the variance is found by using the mean. So we will do that first. I will use the population variance as opposed to the sample variance since our set of numbers is small.
The mean: 8 + 12 + 15 + 17 + 18 = 70 and divide that by 5 to get
and use this to find the variance in the formula:
it is a bit difficult to enter that formula in correctly, but here's how it works mathematically:

Squaring this ensures us that we don't end up with zero, which would be useless.
so
which means that the standard deviation is
s = 3.633
(If you do it with n-1 = 4 in the denominator of the variance, you get a standard deviation of 4.062)
2x+4x-4=2+4x
2x+4x-4x=2+4
2x=6
x=3
25-x=15-3x-10
3x-x= 15-10-25
2x= -20
x= -10
4x=2x+2x+5x-5x
2x+2x+5x-5x-4x
0 . no solution
It should be 35.5 now I gotta reach 20 characters