Question

In: Statistics and Probability

Determine the sample size necessary for estimating the proportion of Ohio teachers that feel anxious about...

Determine the sample size necessary for estimating the proportion of Ohio teachers that feel anxious about teaching online. Suppose you want to be 99% confidence that the proportion is within 4.25 percentage points of the true proportion. Furthermore, suppose a study from a few years ago showed that 72% of Ohio teachers feel anxious about teaching online.

Expert Solution

Solution :

Given that,

= 0.72

1 - = 1 - 0.72= 0.28

margin of error = E = 0.0425

At 99% confidence level the z is,

= 1 - 99%

= 1 - 0.99 = 0.01

/2 = 0.005

Z/2 = 2.58 ( Using z table )

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

= (2.58 / 0.0425)2 * 0.72 * 0.28

=742.93

Sample size = 743

orchestra answered 2 years ago

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