Recall that a margin of error for a 95% confidence interval for process probability can be approximated by the expression 1/ˆšn.
a. Evaluate this expression (to three decimal places) for the following sample sizes: 100, 400, 1,000, 2,000, 8,000, 9,000.
b. Based on your answers in part (a), produce a graph using the following axes and scales. Describe how the margin of error changes with the sample size? Does it increase,decrease, or stay the same?

c. In order to cut the margin of error in half, by how many times must the sample size increase?
d. Which has the bigger impact on the margin of error: increasing the sample size from 100 to 500 (an increase of 400) or increasing the sample size from 8,000 to 9,000 (an increase of 1,000)? Explain.

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1.0 0,8 0.6 - 0.4 - 0.2 0.0 1000 2000 3000 4000 5000 6000 7000 8000 9000 Sample size Margin of error