The amount of time a certain brand of light bulb lasts is normally distribued with a mean of 900 hours and a standard deviation of 55 hours. Out of 720 freshly installed light bulbs in a new large building, how many would be expected to last between 800 hours and 1030 hours, to the nearest whole number?

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Which is f(5) for the function –2x2 + 2x - 3?

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?