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Confidence interval for a random sample of microwave ovens

In a random sample of six microwave ovens, the mean repair cost was $90.00 and the standard deviation was $11.00. Assume the variable is normally distributed and use a t-distribution to construct a 90% confidence interval for the population mean u. What is the margin of error of u?

The 90% confidence interval for the population mean u is ( , ).
Round to 2 decimal places.

The margin of error is ( ).
Round to 2 decimal places.

Solution Preview

The formula would be: C. I. = M ± (z * SE)
Where:
m=mean
z = the degree of alpha - we get it from a z-table: ...

Solution Summary

The solution uses 90% confidence interval for population mean.

$2.19