# Statistics - Confidence Interval

How do you find the Confidence Interval for a particular Confidence Level, such as 95%, for a sample of more than 30 people? Show the exact formulas that you use in this situation to calculate the sample standard deviation and standard error?

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#### Solution Preview

If the sample size is greater than 30, then we use the normal distribution. A typical problem will have the following

Components:

Given: (a) Mean of the sample, M (Say 20) (b) Standard Deviation of the sample, s (Say 1.3) (c) Sample size, n (Say 49)

(d) ...

#### Solution Summary

Step-by-step solution assists with finding the confidence interval.

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