# Statistics

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A researcher wishes to estimate the proportion of adults who have high-spped internet access. What size sample should be obtained if she wishes the estimate to be within .02 with 90% if

A) She uses a previous estimate of 0.48?
B) She does not use any prior estimates?

• Statistics -

Formula to find sample size:
n = [(z-value)^2 * p * q]/E^2
... where n = sample size, z-value is found using a z-table for 90% confidence (which is 1.645), p = .48 (when no value is stated in the problem p = .50), q = 1 - p, ^2 means squared, * means to multiply, and E = .02.

Plug values into the formula and calculate n.

I hope this will help get you started.

• Statistics -

THANK YOU

• Statistics -

A researcher wishes to estimate the proportion of adults who have high-spped internet access. What size sample should be obtained if she wishes the estimate to be within 1% of true proportion

• Statistics -

How do you know what the z-value is? I've never used a z-table.

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