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Modelling with the normal distribution

Modelling with the normal distribution problem 7

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A large number of runners took part in two charity runs to raise money for a new community centre. In the first run, the times to complete the run were normally distributed with mean 46.3 seconds and standard deviation 6.4 seconds.

Find the probability that a randomly chosen runner took more than 55.1 seconds to complete the run.
In the second run, the times to complete the run were normally distributed with mean 39.8 seconds and standard deviation seconds. of the runners took more than 48.6 seconds. Find the value of .

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