Normal Distribution

Question

Answer 1

 z score value of 97.5% is 2.2414 .

( The values of z score taken from z score table )

Mean score μ = 12   standard deviation σ =3

 

2.2414 = ( x - 12 ) / 3

x - 12 = 2.2414*3

x - 12 = 6.7242

x = 6.7242 + 12

x = 18.7242 ≈ 19 min

The time to reach stanely hall is 19 min

The class work will start at 10:10 AM 

The time to start from  dorm is  10:10 -19 min = 9:51 AM

So one has to start from dorm to stanely hall at  9:51 AM .