The formula of the variance of the distribution of sample mean of a random variable X, which it will denoted by 
is
where n is the size of the sample.
Since X is continuously uniform between 3 and 8, you have
Therefore, the variance wanted is 
Answer:
D
Step-by-step explanation:
(0, 0) (0, 1) (1, 2) (1, 3)
For it to be a function each x value should have one y value.
There are two 0's for x and two 1's for x. This is how you can tell it's not a function.
(a) In functional notation, you are asked for C(600).
For this, put 600 where t is in the functional notation C(t).
(b) The value multiplying 8 is 0.5 when the exponent of 0.5 is 1. That is
... t/5730 = 1
Multiplying by 5730 gives
... t = 5730
It will take 5730 years for half the Carbon 14 to be gone.
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Or, you can recognize a fraction is 1 when its numerator is the same as its denominator. That is t/5730 = 5730/5730 = 1 when t=5730.
We determine first the real dimension of the circular fountain by using the scale factor given.
(18 cm) x (4 ft / 3 cm) = 24 ft
Then, calculate for the area of the base of the circular fountain by the equation,
A = πD²/4
where A is are and D is diameter. Substituting,
A = π(24 ft)²/4 = 144π ft² ≈ 452.4 ft²
Thus, the area of the base of the circular fountain is approximately 452.4 ft².
