Use confidence interval formulas for proportions.
CI95 = p + or - (1.96)(√pq/n)
...where √ = square root, p = x/n, q = 1 - p, and n = sample size.
Hint: x = 150, n = 240
Convert all fractions to decimals to work the formulas.
I hope this will help get you started.
Professor York randomly surveyed 240 students at Oxnard University, and found that 150 of the students surveyed watch more than 10 hours of television weekly. Develop a 95% confidence interval to estimate the true proportion of students who watch more than 10 hours of television each week. The confidence interval is:
A. .533 to .717
B. .564 to .686
C. .552 to .698
D. .551 to .739
3 answers
^^^ not a good answer
The answer is B
0.625 +/- (1.960) times the square root of 0.0625(1-0.0625)/240
0.625 +/- (1.960) times the square root of 0.0625(1-0.0625)/240
1 answer