Answer:
20.655
Step-by-step explanation:
might have to round it
Two plus the product of 5 and x
or
the product of 5 and x plus 2
or
5 times x plus two
Answer:
WY= squar root 55 + 4
Step-by-step explanation:
I say it’s c it makes the most sense to me
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