Students find the confidence interval for a population proportion by first finding the critical value and the margin of error.
In Problem 1, students are to find the critical value, the margin of error, and the intervals at both the 95% and 99% level. Critical values are found by using the invNorm command to find the area to the left of that value.
Students can then use their handheld to compute the Confidence Interval without finding critical value and margin of error. They will be able to check their work using the 1-Prop z Interval command.
Encourage students to summarize what they have learned from completing the activity. If desired, discuss the extension with students.
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