Pye and Associates recently conducted a survey to determine the percent of adult county residents who believe that students in public high schools should wear uniforms to school. The telephone poll of 325 adults found that 35% of the adults believe that public high school students should wear uniforms to school. Determine the 95% confidence interval for the true proportion of adults in the county who believe public high school students should wear uniforms.

Question

The 95% confidence interval is % to %.

What is the margin of error?

The margin of error is %. Enter each number as a percent rounded to one decimal. Do not type in the % sign..

I got 29.9 to 40.3 as the interval and 5.2 as the margin of error. Would my answer be correct?

Answer 1

p = .35
n = 325
z = 1.96
E = ('z critical value') * sqrt[p * (1 - p)/n]

E = 1.96 * sqrt [.35* .65/325]

E = 0.0519

p ± E = [.2891, .4019]

The 95% confidence interval is 29.8% to 40.2%.
The margin of error is 5.2.

Answer 2

With a reliability coefficient of 0.81, using classical test theory we would interpret that the:
Answer
a.Amount of error variance to observed variance is 81 percent
b.Amount of true variance to observed variance is 81 percent
c.Instrument has good enough reliability
d.Instrument's validity coefficient would be 0.812

Answer 3

Amount of true variance to observed variance is 81 percent

Answer 4

with the reliability coefficent of 0.81 using the classical theory we would interpret that the