Remark
You have to read this carefully to know what way to write it.
One way you could write it would be
20 * x = 18 where x is the fraction. Now all you need do is divide.
Divide both sides by 20
20/20 * x = 18/20
But you should reduce this fraction. The way to do that is to factor 18 and 20 into primes.
18: 2 * 3 * 3
20: 2 * 2 *5
Cancel out the Highest common factor or 2.
You are left with
<<<< Answer
Answer: (0.24 - 1.96*0.019, 0.24 + 1.96*0.019)
Step-by-step explanation:
We know that the confidence interval population proportion (p) is given by :-
, where = sample proportion.
z* = Critical value (Two -tailed)
SE = standard error
Given : In 2012, about 24% of high-school seniors reported binge drinking (defined as five or more drinks in a row in the past two weeks), a substantial drop since the late 1990s.
SE = 0.019
Significance level =
Two-tailed value corresponds for :
z*=1.96 [Using z-table]
Now, the 95% confidence interval for the proportion of high-school seniors in the sample who would report binge drinking will be :-
Hence, the correct answer = (0.24 - 1.96*0.019, 0.24 + 1.96*0.019)