Answer:
Required largest volume is 0.407114 unit.
Step-by-step explanation:
Given surface area of a right circular cone of radious r and height h is,
and volume,

To find the largest volume if the surface area is S=8 (say), then applying Lagranges multipliers,
subject to,

We know for maximum volume
. So let
be the Lagranges multipliers be such that,



And,



Substitute (3) in (2) we get,



Substitute this value in (1) we get,



Then,

Hence largest volume,

Solution :
It is given that :
Number of students in a random sample majoring in communication or psychology at an university = 250
Total number of students majoring in psychology = 100
Number of students majoring in psychology those who are happy = 80
So number of students majoring in psychology those who are not happy = 20
Total number of students majoring in communication = 250 - 100 = 150
Number of students majoring in communication those who are happy = 115
So number of students majoring in psychology those who are not happy = 35
a). Probability of the students happy with their major choices are

= 0.78
b). Psychology major 
= 0.4
c). Probability of the students who are happy with the communication as the choice of major =
= 0.46
d). Students unhappy with their choice of major given that the student is psychology major =
= 0.018
Answer: the slope is 3/4.
y=mx+b and m is always the slope.