can someone show me the steps to solve these probability questions? Im willing to do the math, I just dont know how

Question

maddisongruby · Answer

attachment

kg1975 · Answer

Sorry  that would be giving away the answer i can not do that Maybe ask someone else Sorry!

kg1975 · Answer

idk how to explain it without giving away the answer

welshfella · Answer

Its been a while since i did these 
I think you have to calculate  a z -score and use the normal distribution chart to read off the result.

z score   =  X - mean
                   --------     =  (X- 62.5) / 2.5
                      std dev

maddisongruby · Answer

so like, what would i make x? is it the 5400?

maddisongruby · Answer

@welshfella would the answer be 2135? for the first one?

phi · Answer

For the first question, they are asking how much of the "population" is "below the mean"