The sample mean is an estimate of the population mean.
The sample mean is exactly equal to the population mean
<h3>How to determine the true statement</h3>
When the population mean is known; the value of the population mean can be used as the sample mean.
This is so because:
The sample mean is an estimate of the population mean.
And it is represented as:

Hence, the true statement is that the sample mean is exactly equal to the population mean
Read more about sample mean at:
brainly.com/question/12892403
Answer: 
Step-by-step explanation:
The measure of the third unknown arc is
.
So, 
Y= -1 +1/1. I hope it’s correct if not u can use desmos
I think it’s line graph but I think I’m completely wrong-
A) Demand function
price (x) demand (D(x))
4 540
3.50 810
D - 540 810 - 540
----------- = -----------------
x - 4 3.50 - 4
D - 540
----------- = - 540
x - 4
D - 540 = - 540(x - 4)
D = -540x + 2160 + 540
D = 2700 - 540x
D(x) = 2700 - 540x
Revenue function, R(x)
R(x) = price * demand = x * D(x)
R(x) = x* (2700 - 540x) = 2700x - 540x^2
b) Profit, P(x)
profit = revenue - cost
P(x) = R(x) - 30
P(x) = [2700x - 540x^2] - 30
P(x) = 2700x - 540x^2 - 30
Largest possible profit => vertex of the parabola
vertex of 2700x - 540x^2 - 30
When you calculate the vertex you find x = 5 /2
=> P(x) = 3345
Answer: you should charge a log-on fee of $2.5 to have the largest profit, which is $3345.