Please show me excel formulas for the following question Let

Please show me excel formulas for the following question. Let X be normally distributed with mean u=120 and standard deviation o=20 . a. Find P(X 86) b. Find P(80 X 100)c. Find x such that P(X x) =0.40 d. Find x such that P(X > x) =0.90

Solution

Since mean is 120 and standard deviation is 20 so

a) For P(X 86) Type =NORM.DIST(86,120,20,TRUE) which gives 0.044565

b) For P(80 X 100) type =NORM.DIST(100,120,20,TRUE)-NORM.DIST(100,120,20,TRUE) Which gives 135905

c ) For P(X x) =0.40 type =NORM.INV(0.4,120,20) which gives x=114.93

d) Since P(X > x) =0.90 so P(X<x)=0.1 Now type =NORM.INV(0.1,120,20) which gives x=94.37