5 An electronics company produces batteries with a lifespan that is normally distributed
with a mean of 182 days and a standard
deviation of 10 days.
a Find the probability that a randomly
selected battery lasts longer than 190 days.
b In a sample of seven batteries chosen
for a quality control inspection, find the
probability that no more than three of
them last longer than 190 days.
404, c If a battery is guaranteed to last up to
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165 days, find the probability that the
battery will cease to function before the
guarantee runs out.
d Hence predict the number of batteries in
a batch of 10000 that would not last the
duration of the guarantee.
work each