Just took the test, the answer is C.
:)
Variance is the standard deviation squared but we're not going to use that now. Let's first calculate the mean:
mean = (17+13+13+22+11+20)/6 = 16.
Now for each value, let's see how far it is from this mean. We'll square these distances and average them. That's our variance.
17 distance 1 squared = 1
13 distance 3 squared = 9
13 distance 3 squared = 9
22 distance 6 squared = 36
11 distance 5 squared = 25
20 distance 4 squared = 16
Now average these outcomes:
variance = (1+9+9+36+25+16)/6 = 16.
So the variance by coincidence is the same as the mean.
Answer C is your answer.
6(x-2.5) ≥ 8-6(3.5+x)
A number is before a parenthesis. The first step is to multiply.
6(x-2.5) = 6x -15
8-6(3.5+x)
2(3.5+x)= 7+2x
6x-15≥7+2x
Now solve
6x-15≥7+2x
-2x -2x
(-2x+2x)= They cancel out
(6x-2x)= 4x
4x-15≥7
+15 +15
4x≥22
/4 /4
You get= x≥5.5
As soon as possible after the lecture
