Problem 1 [4 pts]: The maintenance cost of machines are uniformly distributed from 0 to 160 (dollars). If a random sample of 75 machines is taken from a factory, (a). find the mean aggregate (total) maintenance cost for a sample of 75 machines.

$6,000

Step-by-step explanation:

The mean value of a sample is assumed to be the same as the mean of the population. The mean of a uniformly distributed variable between 0 and 160 is:

If the mean cost for each machine is $80, the mean aggregate cost for a sample of 75 machines is:

The mean aggregate maintenance cost is $6,000.

the answer   is 200

step-by-step explanation:

this is a problem about poisson probabilities.   i don't know if you've

already studied poisson distributions, or if you have a place to look

to read more about the subject.  

here's how you can see a poisson distribution coming.   when there are

a lot of events that may happen at any time (or any place), and when

you're counting how many of them happen at a particular time (or a

particular place), and each event is independent of the others, then

the result is a poisson distribution.   this is roughly true for the

chocolate chips; one chip being in a cookie has only a small effect on

the probability that another chip will be in the cookie.

once you know you have a poisson distribution, you know a lot.   there

is only one parameter to a poisson distribution, so if you know the

mean, you know everything.   the form of the distribution is

  probability of n chips = {[e^(-x)]*(x^n)} / (n! )

77

step-by-step explanation: