Answer:
1/9 x 1/9 just do it across... 1/81
Step-by-step explanation:
Answer and work in this picture:
<span>It looks like you're supposed to pick a combination of two answers:
an absolute-value inequality, and
a sentence describing the meaning of that inequality.
We've got two choices for each, and therefore four possible combinations of choices.
First, let's tackle the sentence description. We're told that
"it [the cost] could differ [from the average of $32] as much as $8."
That sets a maximum value for the difference; it's UP TO $8.
If the cost is less than average, it could be as little as
$32 - $8 = $24
and if the cost is more than average, it could be as much as
$32 + $8 = $40.
So the medication costs range from $24 to $40, and we want an answer that states that.
Now for the inequalities:
|x - 32| describes the SIZE of the difference. Using the absolute-value function means we don't distinguish between
x - 32
and
32 - x
as far as our interests are concerned; we eliminate the sign from the subtraction and just look at the size of the difference.
But in the case we're looking at, we've got a MAXIMUM value for the difference; it can't be more than 8. The inequality
|x - 32| ≥ 8
says the difference is 8 or MORE, so we don't want that. Instead, we want
|x - 32| ≤ 8
which says the difference is anywhere from 0 to 8.
Combining these conclusions, we see we're looking for this answer:
|x - 32| ≤ 8; The medication costs range from $24 to $40
which is the third one listed.</span>
Ratio of classes A, B, C = 4 : 6 : 5, respectively
4 + 6 + 5 = 15
So, class A represents 4/15 of the TOTAL population
Class B represents 6/15 of the TOTAL population
Class C represents 5/15 of the TOTAL population
So, weighted average of 3 groups combined = (4/15)(65) + (6/15)(80) + (5/15)(77)
= 260/15 + 480/15 + 385/15
= 1125/15
= 75
Answer: B
