Answer:
Stratified sampling
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
Population divided into groups, and random samples are drawn from the groups. This is a mark of stratified sampling.
Answer:
a) You roll a die 25 times. Let X be the number of times that you roll "3".
* Is a Binomial
b) The SJSU football team will play 12 games next season. They have a 70% chance of winning each conference game and a 60% chance of winning each nonconference game. Let X be the number of games the SJSU football team wins next season.
* Not a Binomial because probability of success is not constant
c) Evelyn has a 75% chance of getting an A in each class she takes. Let X be the number of times Evelyn earns an A during four years at SJSU.
* Is a Binomial
The awnser to this problem is either 12 or 7 by using multiplication or addition
Look up online "equation calculator" and it should be the first one to appear, "Symbolab" supper easy way to help you with problems!
Here you go. A quick picture to demonstrate the problem. Hope this helps!! <span />