1) The manufacturer of a laser printer reports the mean number of pages a cartridge will print before it needs replacing is 12,375. The distribution of pages printed per cartridge closely follows the normal probability distribution and the standard deviation is 645 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 90 percent of the time? (Round z value to 2 decimal places. Round your answer to the nearest whole number.)
Pages:
2) According to the "January theory," if the stock market is up for the month of January, it will be up for the year. If it is down in January, it will be down for the year. According to an article in The Wall Street Journal, this theory held for 24 out of the last 34 years. Suppose there is no truth to this theory; that is, the probability it is either up or down is 0.5.
What is the probability this could occur by chance? (Round your answer to 6 decimal places.)
Probability: