Question

The 47th Annual PDK/Gallup Poll of the Public’s Attitudes toward the Public Schools, conducted in May 2015, sampled 4,500 adult Americans and found that 64% feel there is too much emphasis on standardized testing in the public schools in their community.

Using the quick method, the estimated margin of error for conclusions having 95% confidence about the entire adult population of adult Americans is ___%?

Answer 1

1.3809%

Explanation:

Given ;

Sample size, n = 4500

Phat = 64% = 0.64

The margin of error :

Zcritical * √[Phat(1 - Phat) / n]

At 95% confidence level:

Zcritical at 95% = 1.96

Margin of Error :

1.96 * √[0.64(0.36) / 4500]

1.96 * 0.0071554

= 0.0138099

= 0.0138099 * 100%

= 1.3809%