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
You have to move the decimal point from the end to between the 6 and 5 then count how many spaces you moved it because this will become the power on the 10.
6.5 x 10^7
Answer:
-30, 210 and 330 degrees
Step-by-step explanation:
Given the expression Sin x = - 1/2
x = arcsin(-1/2)
x = -30 degrees
Since sin is negative in the third and fourth quadrant
x = 180 + 30
x = 210 degrees
In the fourth quadrant
x = 360 - 30
x = 330
Hence the value of x within the interval -360 < x < 360 are -30, 210 and 330 degrees
V: volume of a cone = (πr²h)/3 = 104.67 in³
π: pi = 3.14
r: radius = 1/2 diameter = [unknown]
h: height = 4 in
V = (πr²h)/3
V = r²(πh)/3
r² = (3V)/(πh)
r² = (3 ×104.67)/(3.14 × 4)
r² = 25
r = √25
r = 5 (but remember the radius is only 1/2 the diameter)
thus . . .
<u><em>d = 10 in </em></u>
When an spherical balloon volume is increasing at the rate of
then the diameter of the balloon is increasing 
How can we find the rate of change of balloon's diameter ?
The volume of a spherical balloon is 
In form of diameter we can write as

Now we will differentiate both sides wrt to
we get

Given in the question 
thus when we substitute the values we get

Learn more about the differentiation here:
brainly.com/question/28046488
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