10,000,000+2,000,000+
400,000+30,000+90
A = P(1+(r/n))^nt
A = 500(1+(.09/1))^1<span>∗4
A = 500(1.09)^4
A = 705.79</span>
Answer:
a. increase the sample size
Step-by-step explanation:
The width of a confidence interval is twice the margin of error, which is given by:

In which
is the standrd deviation of the population, n is the size of the sample, and z is the confidence coefficient(the higher the confidence level, the higher z is).
The only of those variables which is direct proportional to M is the sample size. This means that if we want to decrease the width of M, we need to increase the sample size.
So the correct answer is:
a. increase the sample size