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)
The answer is 6 because you do this
1/3 of 18 divide 18 by 3 amd get 6
Answer:
x=-2
Step-by-step explanation:
4+8x=-12
-4 -4
8x = -16
/8 /8
x = -2
Answer:
-25/12
Step-by-step explanation:
first, you need a common denominator. in this case, it's 12.
-1/3=-4/12
-7/4=-21/12
and then you add
-4+-21=-25
so -25/12 is your answer