The area under the standard normal distribution between 25 a

The area under the standard normal distribution between -2.5 and 1.5 is?

Solution

Normal Distribution
Mean ( u ) =0
Standard Deviation ( sd )=1
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
To find P(a < = Z < = b) = F(b) - F(a)
P(X < -2.5) = (-2.5-0)/1
= -2.5/1 = -2.5
= P ( Z <-2.5) From Standard Normal Table
= 0.00621
P(X < 1.5) = (1.5-0)/1
= 1.5/1 = 1.5
= P ( Z <1.5) From Standard Normal Table
= 0.93319
P(-2.5 < X < 1.5) = 0.93319-0.00621 = 0.927