1. Assume that there is a normal distribution with a mean of 4 and standard deviation equal to 2, find P (3 less or equal than x less or equal than 6)

2.Assume that there is a normal distribution with a mean of 15 and standard deviation equal to 4,

find P (10 less or equal than x less or equal than 26)

3.Assume that there is a normal distribution with a mean of 40 and standard deviation equal to 15,

find P (50 less or equal than x less or equal than 70)