Answer:
2.5 cm
Step-by-step explanation:
Convert the mixed numbers to improper fractions, then find the LCD and combine.
Answer: -4/15
Step-by-step explanation:
- 2/3 - (-2/5)
= -2/3 + 2/5
= -10/15 + 6/15
= -4/15
They all add 3 then subtract it by 4
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 B. Adjacent angles. They both have a meeting point and don't overlap.
The answer isn't A. because both angles don't add up to 90°.
The answer isn't C. because both angles aren't 90°.
The answer isn't D. because both angles don't add up to 180°.
Hope this helps! :)
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