Normal distribution exercise

[marintta]

The maximum recommended load for an elevator is 300kg and the respective
capacity has been fixed at 4 users. Assume that lift users have a weight normally
distributed with an average of 70 kg and standard deviation of 5 kg.
a) How likely is it that a user's weight will exceed 60 kg?
b) How likely is it that a user will have a weight between 65 and 75 kg?
c) Knowing that a user weighs more than 60 kg, what is the probability that his
weight does not exceed 75 kg?
d) What is the most likely weight? And the median weight? Justify.
e) What weight will 25% of users exceed?
f) Calculate the probability of 4 users exceeding the maximum recommended
load.
g) 4 users entered the elevator. How likely are 2 of them to weigh more than 76.4
kg?


I already did a,b,c but I have problem doing other ones

 

[Steven G]

Can you tell us what problem you are having with part d? It is hard to offer help if you do not tell us where you are stuck. Please follow the forum's posting guidelines by posting the work you have done for part d and then a volunteer will be able to help you.