SOLUTION: Suppose a car manufacturer believes its windscreen wipers will last on average for three years on their cars if driven by a typical driver in the province. Moreover, the manufactur
Algebra ->
Probability-and-statistics
-> SOLUTION: Suppose a car manufacturer believes its windscreen wipers will last on average for three years on their cars if driven by a typical driver in the province. Moreover, the manufactur
Log On
Question 1159526: Suppose a car manufacturer believes its windscreen wipers will last on average for three years on their cars if driven by a typical driver in the province. Moreover, the manufacturer believes the lifetime of the wipers under such conditions is Normally distributed with a standard deviation of two years. Find the probability that, if on a car driven by a typical driver, a windscreen wiper lasts for a time that is not within 1.2 years of the mean lifetime.
The probability is:
I tried to find (|x-3|>1.2) but I keep getting it wrong so I know I'm going wrong somewhere in the steps. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! within 1.2 years of the mean lifetime is within 0.6 sd (1.2/2)
so want z<-0.6 and z>0.6
or 1- z (-1.2, 1.2)=1-0.7699=0.2301
z=(x-mean)/sd
