A) X = 1/3
B) X = 17/5x
C) X = 1/5
D) X = 1/6
Answer:
Option C is correct
It is a stratified random sample because parents were randomly selected from each group.
Step-by-step explanation:
I'll talk about the different types of sampling.
1) Random Sampling
In random sampling, each parent would have an equal chance of being surveyed. If this particular scenario wanted to use random sampling, they would have used computer generated random numbers for the parents and surveyed them, not just pick random parents equally from two cities.
2) Systematic sampling is easier than random sampling. In systematic sampling, a particular number, n, is counted repeatedly and each of the nth parent is picked to be sampled.
3) Convenience Sampling
This is the worst sampling technique. It is also the easiest. In Convenience sampling, they just survey the first set of parents that they find.
4) Stratified Sampling
Stratified sampling divides the population into groups called strata. A sample is taken from each of these strata using either random, systematic, or convenience sampling.
So, for this question, random sampling is used to pick a sample from the two strata (from the 2 cities). This is why the sampling used in this question is a stratified random sampling technique.
5) Cluster sampling
Cluster Sampling divides the population into groups which are called clusters or blocks (the different cities). The clusters are selected randomly, and every element in the selected clusters is surveyed (each parent in the selected cities, is surveyed!).
Hope this Helps!!!
y = (x+2)(x-6)(x+7)
(x+2)(x+7)
x^2 - 6x + 2x - 12
x^2 - 4x - 12
(x^2 - 4x - 12)(x + 7)
x^3 + 7x^2 - 4x^2 - 28x - 12x - 84
x^3 + 3x^2 - 40x - 84
y = x^3 + 3x^2 - 40x - 84