Confidence Intervals for mu (when sigma is unknown
and n<40)
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When sigma is unknown and n<40, you want to conduct a CI that uses t.
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To do this, enter your data into C1. Then go to Stat, Basic Statistics,
1 sample t.
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Your screen should look like this.
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Enter the variable that you want and the known standard deviation. Now
click on Options.
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Make sure that you entered the correct confidence level.
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Next pick the type of confidence interval or bound.
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If you want a confidence interval select, "not equal" as your alternative.
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If you want a confidence bound, select "less than" for a upper bound or
"greater than" for an lower bound.
Note: Your screen may look a little different; however,
you should have the same boxes to fill in for Confidence and Alternative.
Your output may look like the following.