The manufacturer of a laser printer reports the mean number of pages a cartridge will print before it needs replacing is 12,425.
the distribution of pages printed per cartridge closely follows the normal probability distribution and the standard deviation is 595 pages. the manufacturer wants to provide guidelines to potential customers as to how long they can expect a cartridge to last. how many pages should the manufacturer advertise for each cartridge if it wants to be correct 99 percent of the time?
A suitable probability app shows the 1st percentile to be at about 11040 pages.
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The app shown has an error in the first decimal digit. The number is closer to 11040.82301. We expect the manufacturer would round to the nearest 10 or 50 or 100 in advertising.
The math I used is probably not the quickest way, but for me, the easiest. 25*5=125 25+20=45 45*7=315 125+315=440 25*4=100 440+100=540 5+7+4=16 B is your answer.
because if a human is 3 meters tall and cast 2 times the length of himself then if a building casts 25 meters then it should be 2 times less than its shadow.
