00:01
A mail order computer business has six telephone lines.
00:03
X is the number in use at a specified time.
00:07
Part a, we want to get the cumulative distribution function.
00:12
So we've got the values of x, and we're going to have c of x.
00:18
So x can be 0, 1, 2, 3, 4, 5 or 6.
00:25
And the cumulative is a running total of the probabilities.
00:31
It is the probability of getting x or fewer in use.
00:42
So for 0 .0, it's still the same, that's 0 .1.
00:46
But for 1, we have to add on this new value, 0 .15, to get a total of 0 .25.
00:52
The probability of them having 1 or fewer lines in use is 0 .25.
00:59
To get to 2, we add on the new value...