calculus
posted by PHILLIP .
A MANUFACTURE OF LIGHTBULBS HASS SAMPLED 40 BULBS IN ORDER TO DETERMINE THE POPULATION MEAN LIFE OF THE BULBS. tHE SAMPLE MEAN WAS 1200 HOURS WITH A STANDARD DEVIATION OF 100. tHE MANUFACTURER WOULD LIKE TO KNOW, WITH 95% CONFIDENCE, THE INTERVAL VALUES FOR THE POPULATION MEAN.
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