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:
The answer is C. AAA is not a congruency postulate because the side lengths may be different sizes although the angles are the same.
Answer:
Algebra
Step-by-step explanation:
Answer: 1
Step-by-step explanation:
3 copies of 1/3 would be 1/3+1/3+1/3= 1
Answer:
nah
Step-by-step explanation:
the distance between H and G is longer than the distance between C and D making it not congruent