a city needs
to
perform some road maintenance and will rent excavator m
achines from a
company. Each excavator will work at least 1 hour, but no more than 4 hours at a time.
It is known that
the working time of each excavator is evenly distributed.
a)
What is the distribution of one excavator’s working time?
b)
What is the probabi
lity that an excavator works more than 3.5 hours?
c)
Given that an excavator has already worked for 2.5 hours, what’s the probability that it
works
at least
1
more
hour
until it is given a
rest?
d)
What amount of time represents the highest 30% of excavator working time?
e)
The rental fee of each excavator is 200 dollars per hour, if the city rents 3 excavators, what is the expected rental fee
per day?
1 answer
At a cell phone battery plant, 5% of cell phone batteries produced are defective. A quality control engineer randomly collects a sample of 50 batteries from a large shipment from this plant and inspects them from defects. Find the probability that A. None of the batteries are defective