If the cosmic radiation to which a person is exposed while flying by jet across US is a random variable having mean 4.35 mrem and standard deviation 0.59 mrem, find the probabilities that the amount of cosmic radiation to which a person will be exposed on such a flight is: (a) Between 4.00 and 5.00 mrem
(b) At least 5.50 mrem
(c) Less than 4.00 mrem

a

b

c

Step-by-step explanation:

From the question we are told that

   The mean is  

    The standard deviation is  

Generally the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is between 4.00 and 5.00 mrem is mathematically represented as  

Here

=>

=>

=>

From the z -table the probability of  ( Z <  1.1017  ) and  (Z < -0.59322)   are

and

So

=>    

=>      

Generally the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is  At least 5.50 mrem is mathematically represented as

Here

From the z -table the probability of (Z< 1.94915) is  

So

=>    

Generally the probability that the amount of cosmic radiation to which a person will be exposed on such a flight is less than 4.00 mrem is mathematically represented as

From the z -table the probability of (Z< 1.94915) is  

So

i belive those are the ones that are under 90 degreese.