Answer: D. A single number calculated from the sample that estimates a target population parameter is called a point estimator.
An interval estimator is a range of numbers that contain the target parameter with a high degree of confidence.
Step-by-step explanation:
When we evaluate an range of values for an unknown population parameter, then it is known as interval estimation .
A single number evaluated from the SAMPLE that estimates an unknown population parameter is known as a point estimator.
The general difference between point and interval estimator is the point estimator is a single value of target parameter while interval estimator is a range of numbers to estimate the values about the unknown population.
In this equation y would equal 4 or it could be 1
Given cost function is
c(x) = 
(20 ≤ x ≤ 400)
where x is the number of thousands of square feet
total revenue will be $0.2 million dollars per thousand square feet
Revenue is 0.2 millions per thousand square feet. we know x is the number of thousand of square feet
So R(x) = 0.2x
We know Profit = Revenue - Cost
P(x) = R(x) - C(x)
combine like terms
Profit function is
