Assume the printercartridgesin average can print 12,000 pages with 800 pages as its standard deviation (= 12000, = 800), and it is a bell-shaped distribution for the number of pages (X) it can print before running of of ink.(X is a random variable, isn't it?)

What is the chance that your cartridge can print between9,999 to10, 969 pages?That means in Math: P(9,999 < X < 10,969)= ?

4 decimals