Could someone please help me on these two superhard questions:
On average I recieve one text message every 15.9 hours. Assuming that the time between successive text messages has an exponential distribution, what is the probability that I have to wait between 6 and 34 hours for the next text message to arrive?
I need to schedule an appointment with a student, but before the appointment there is a commitee meeting. The meeting will last a random length of time, exponentially distributed with mean 68 minutes. How many mins after the start of the meeting should I set the appointment if i want to be 87% certain that the meeting is finished before the time scheduled for the appointment?
I just don't get what they're asking us to do. Please can someone help me. Arrghhh I hate stats!
...for the 2nd time this year