Question

7. You want to estimate the proportion of students at OSU who use the app TikTok. You select a random sample of 280 OSU students and find that 51% use TikTok. If you want to construct a 90% confidence interval, what will the margin of error be? Again, attempt to round as little as you can along the way, and choose the answer below that is closest to what you obtain. A. 5.8% B. 6.2% C. 2.7% D. 3.3% E. 4.9%

Answer 1

Solution :

Given that,

n = 280

Point estimate = sample proportion = = 51%=0.51

1 - = 1-0.51=0.49

At 90% confidence level

= 1 - 90%  

= 1 - 0.90 =0.10

/2 = 0.05

Z/2 = Z0.05 = 1.645 ( Using z table )

Margin of error = E = Z / 2 * (( * (1 - )) / n)

= 1.645 (((0.51*0.49) / 280)

= 0.049

=4.9%

CORRECT OPTION E