Question

For this problem, please round your critical value to 3 decimal places: Major television networks want to know what percentage of NBA Finals viewers also plan to watch the show that airs after it. What is the minimum sample size they need to survey to be within 3 percent of the true proportion at 98% confidence?

Answer 1

Solution :

Given that,

= 0.5 (0.5)

1 - = 1 - 0.5 = 0.5

margin of error = E = 3% = 0.03

At 98% confidence level the z is,

= 1 - 98%

= 1 - 0.98 = 0.02

/2 = 0.01

Z/2 = 2.326 ( Using z table )

Sample size = n = (Z/2 / E)2 * * (1 - )

= (2.326 / 0.03)2 * 0.5 * 0.5

=1502.8544

Sample size = 1503