I am struggling on a Probabilty question about paint being applied to cars.
The table needed is as follows:
_____________Mean ____Standard Deviation
Primer_________3.7__________1.2
Undercoat______3.9__________0.9
Top Coat_______4.0__________0.75
(I hope it is easy to follow)
My questions about this are:
1. How do I find the total amount of paint used on average on each car?
2. What percentage of cars will use less than 3 litres of Top Coat?
3. The probability that a car, selected at random, will use between 2.3 litres and 4.5 litres of undercoat?
4. What percentage of cars will use more than 3.2 litres of Primer?
5. If a car receives less than 2 litres of top coat there is a quality issue about this paintwork. The company requires that no more than 2% of the cars should present this problem. The amount of paint dispensed can be adjusted. Determine a new mean such that this quality requirement will just be satisfied. Use an appropriate standard deviation from the table.
We can assume that they follow a Normal Distribution
I've been stuck on this for the past 2 days, I really cannot get my head around it for some reason.
Thanks for any help.