Answer: there is no N in the equation
Step-by-step explanation:
a) The first integral corresponds to the area under y = f(x) on the interval [0, 3], which is a right triangle with base 3 and height 5, hence the integral is

b) The integral is zero since the areas under the curve over [3, 4] and [4, 5] are equal but opposite in sign. In other words, on the interval [3, 5], f(x) is symmetric and odd about x = 4, so

c) The integral over [5, 9] is the negative of the area of a rectangle with length 9 - 5 = 4 and height 5, so

Then by linearity, we have

Answer:
This sampling method used in this question is the stratified sampling method.
Step-by-step explanation:
There are about 5 known sampling methods.
- Random Sampling
In random sampling, each member of the population has an equal chance of being surveyed. All the students are given a number and random numbers are generated to pick the students to be surveyed.
- Systematic sampling
This is easier than random sampling. In systematic sampling, a particular number, n, is counted repeatedly and each of the nth student is picked to be sampled.
- Convenience Sampling
This is the worst sampling technique. It is also the easiest. In Convenience sampling, the surveyor just surveys the first set of students that they find.
- Cluster sampling
Cluster Sampling divides the population into groups which are called clusters or blocks. The clusters are selected randomly, and every element in the selected clusters is surveyed.
- Stratified Sampling
Stratified sampling divides the population into groups called strata. A sample is taken from all or some of these strata using either random, systematic, or convenience sampling. This is evidently the answer to the question as the students are divided into homerooms (strata) and samples are now randomly taken from 3 randomly selected strata.
Hope this Helps!!!