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
Answer:
Jenna sold 280 boxes, Becca sold 105 boxes.
Step-by-step explanation:
For every 3 boxes B sold, J sold 8 boxes and ended with a total of 385 boxes sold.
3b+8j=385
From how the question is asked, we can assume that each round of sales would equal 11 total sales. (3b+8j=11)
Knowing the sales take place in intervals of 11, we can solve the problem by doing 385/11.
385/11=35
Finally, with 35 rounds of sales happening and knowing Jenna sells 8 while Becca sells 3 at each one, all that's left to do is multiply.
8x35=280
3x35=105
To be sure we can check our answer by adding them together, 280+105=385.
(1 + 1 + 1 + 1 + 1 + 1 + 1
) and (
) represents the amount of green paint that Candita used drawing green lines on the painting.
I think it would be 315. because 4.5*70..but im not sure