Answer:

Step-by-step explanation:
Given
Required
Determine the area in terms of time
From the question, we have:
-> radius per time
and
--> area from radius
The interpretation of the question is to find the composite function: a(t)
If
, and
, the
Substitute 0.5t for r



The First person that wrote there answer is correct
Answer: $ 67.03
Step-by-step explanation:
Given : The average expenditure in a sample survey of 50 male consumers was $135.67, and the average expenditure in a sample survey of 38 female consumers was $68.64.
i.e. 
The best point estimate of the difference between the two population means is given by :-

Hence, the point estimate of the difference between the population mean expenditure for males and the population mean expenditure for females : $ 67.03