If the Standard Deviation of the Lifetimes of Vacuum Cleaners

question 87

Short Answer

If the standard deviation of the lifetimes of vacuum cleaners is estimated to be 300 hours, how large of a sample must be taken in order to be 97% confident that the margin of error will not exceed 40 hours?

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Definitions:

Variance

A statistical measure of the dispersion of data points in a dataset, quantifying how far each data point lies from the mean.

Sum of Squared Deviations

The total of the squared differences between each observation and the mean of a dataset.

Standard Deviation

An indicator used to assess the degree to which data points diverge or scatter around the average value.

Range

The difference between the highest and lowest values in a dataset, showing the spread of the data.