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
The answer is c. You distribute the X to the F and G. f(x) + g(x), which is x + 2.
Answer:
8c - 7r + 10p - 20e
Step-by-step explanation:
Subtract (20c + 15r + 75p + 50e) - (12c + 22r + 65p + 70e)
(20c + 15r + 75p + 50e) - (12c + 22r + 65p + 70e)
Open bracket
20c + 15r + 75p + 50e - 12c - 22r - 65p - 70e
Collect like terms
= 20c - 12c + 15r - 22r + 75p - 65p + 50e - 70e
= 8c - 7r + 10p - 20e
You re write the equation with parentheses as (8x5)+(4x2)+(3x2).
Answer:
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