In: Statistics and Probability
The Travel Channel wants to conduct a survey of adults who take weekend vacations to Las Vegas. If the channel wants to be 97% confident that the sample percentage is in error by no more than 1.75 percentage points, how many adults must be surveyed?
Solution :
Given that,
= 0.5 ( assume 0.5)
1 - = 1 - 0. 5= 0.5
margin of error = E = 0.0175
At 97% confidence level the z is ,
= 1 - 97% = 1 - 0.97 = 0.03
/ 2 = 0.015
Z/2 = Z0.015 = 2.17 ( Using z table )
Sample size = n = (Z/2 / E)2 * * (1 - )
= ( 2.17/ 0.0175)2 * 0.5 * 0.5
= 3844
Sample size =3844