Porisma

A hint to get started

Find cutoffs from left-tail and right-tail areas

If X∼N(100,62)X\sim N(100,6^2), find

(i) aa such that P(X<a)=0.8907P(X<a)=0.8907 and

(ii) bb such that P(X>b)=0.770P(X>b)=0.770.

CJC · Lecture · Example 2

Identify the mean and take the square root of the variance.

Convert the event to an interval and sketch the shaded area.

Use normalcdf with lower bound, upper bound, mean and standard deviation in that order.

Read the worked solution