Answer:
a
The 90% confidence interval that estimate the true proportion of students who receive financial aid is
b
Step-by-step explanation:
Considering question a
From the question we are told that
The sample size is n = 200
The number of student that receives financial aid is
Generally the sample proportion is
=>
=>
From the question we are told the confidence level is 90% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of is
Generally the margin of error is mathematically represented as
=>
=>
Generally 90% confidence interval is mathematically represented as
=>
Considering question b
From the question we are told that
The margin of error is E = 0.03
From the question we are told the confidence level is 99% , hence the level of significance is
=>
Generally from the normal distribution table the critical value of is
Generally the sample size is mathematically represented as
=>
=>