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:
$5.71
Step-by-step explanation:
20-5.88=14.12
14.12-8.41=5.71
Answer:
Urban, 2.1 mins
Step-by-step explanation:
36 ÷ 3 = 2 (Gorge's)
42 ÷ 2 = 2.1 (Urban)
Answer:104ft^3
Step-by-step explanation:
volume=length x width x height
Volume=13 x 4 x 2
Volume=104ft^3
Answer:

Step-by-step explanation:
cot(-11pi/6)=cot(-pi-5pi/6)= -cot(5pi/6)=cot(pi/6)=
≈1.73