Probability Probability Probability A sample of PX 1037

Probability =

Probability =

Probability =

A sample of P(X > 1037) Probability = P(X 1127) Probability = B.sigma = 180. Find each of the following: A. mu = 1070 and n= 25 observations is drawn from a normal population with

Solution

Normal Distribution
Mean ( u ) =1070
Standard Deviation ( sd )=80
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
Normal Distribution
Mean ( u ) =1070
Standard Deviation ( sd )=80
Normal Distribution = Z= X- u / sd ~ N(0,1)                  
a)
P(X > 1127) = (1127-1070)/80
= 57/80 = 0.7125
= P ( Z >0.713) From Standard Normal Table
= 0.2381
b)
P(X < 998) = (998-1070)/80
= -72/80= -0.9
= P ( Z <-0.9) From Standard Normal Table
= 0.1841                   c)
c)
P(X > 1037) = (1037-1070)/80
= -33/80 = -0.4125
= P ( Z >-0.413) From Standard Normal Table
= 0.66