Explain probability using normal distribution.
If the expanse of cosmic radiation to which a person is exposed while flying by jet across the US is a random variable having the normal distribution with µ=5.35 mrem and σ = 0.59 mrem. What is the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is
1) Between 3.50 and 6.5 mrem
2) At most 7.5 mrem