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
}
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

(co 3) the times that customers spend in a book store are normally distributed with a mean of 39.5 minutes and a standard deviation of 9.4 minutes. a random sample of 25 customers has a mean of 36.1 minutes or less. would this outcome be considered unusual, so that the store should reconsider its displays? no, the probability of this outcome at 0.035, would be considered usual, so there is no problem yes, the probability of this outcome at 0.035, would be considered unusual, so the display should be redone no the probability of this outcome at 0.359 would be considered usual, so there is no problem yes, the probability of this outcome at 0.965 would be considered unusual, so the display should be redone