Question

-For a Normal distribution with μ=5.5 and σ=1.4
What proportion of observations have values less than 2? (Round to 4 decimal places)

-A manufacturer knows that their items lifespans are normally distributed according to N(9.3,1.4)N(9.3,1.4).
What proportion of the items' lifespans will be longer than 11 years?  

Answer 1

#The R-code is
round(pnorm(-2.5),4)
[1] 0.0062
1-round(pnorm(1.4368),4)
[1] 0.0754