Answer:
b
Step-by-step explanation:
the answer is b because you add all those together then boom
Answer:
(7x-3)/-1
Step-by-step explanation:
swap the x and y and then move the y by itself
x=(3-y)/7
7x=3-y
7x-3=-y
(7x-3)/-1=y
Answer:

--- Variance
Step-by-step explanation:
Given

Solving (a): Calculate the mean.
The given data is a grouped data. So, first we calculate the class midpoint (x)
For 51 - 58.

For 59 - 66

For 67 - 74

For 75 - 82

For 83 - 90

So, the table becomes:

The mean is then calculated as:



-- approximated
Solving (b): The sample variance:
This is calculated as:

So, we have:


-- approximated
Literally just plug it in
6(7) + 5(-4) - 42 = 0
42 -20 -42 = 0
-20 = 0
Not a solution.
Answer: the anwser is 5 trust me
Step-by-step explanation: