- #1
kukumaluboy
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Homework Statement
c. The life of a certain brand of battery is normally distributed with a mean of 4 years and a
standard deviation of 1. 2 years.
i. If a battery is selected at random, what is the probability that it will last for more than 6
years? (5 marks)
ii. How long a warranty period should the manufacturer provide if he is willing to replace
at most 5% of all the batteries sold? (5 marks)
Homework Equations
The Attempt at a Solution
Part (i) i can do. Part (ii) dun understand. 5% of all batteries sold? how many are they?