Answer:
19.35% probability that five will have completed four years of college
Step-by-step explanation:
For each individual chosen, there are only two possible outcomes. Either they have completed fourr years of college, or they have not. The probability of an adult completing four years of college is independent of any other adult. So the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
28% of individuals
This means that 
For a sample of 15 individuals, ages 25 and older, what is the probability that five will have completed four years of college?
This is P(X = 5) when n = 15. So


19.35% probability that five will have completed four years of college
There is no answer, the equation is false.
Answer: It is believed that exactly 20% of Evergreen Valley college students attended the opening night midnight showing of the latest harry potter movie.
Step-by-step explanation:
Since we have given that
n = 84
x = 11
So, 
p = 0.20
So, hypothesis:

so, test statistic value would be

At 1% level of significance, critical value would be
z= 2.58
Since 2.58>-1.604
So, We will accept the null hypothesis.
Hence, It is believed that exactly 20% of Evergreen Valley college students attended the opening night midnight showing of the latest harry potter movie.
Answer:
Check.
Step-by-step explanation:
To prove it we need to know that for two matrices A and B we have that:
det(AB) = det(A)*det(B) and
. Now:





.
Notice the 7) 1st sequence, and the 8) second one