Question

A study of social mobility in America examined the social class attained by the sons of lower class fathers. Social classes were numbered from 1 to 5 with 1 representing the lower class and 5 the higher class. Consider the random variable X to the class of a randomly chosen son. The study found the following distribution:

Son's Class 1 2 3 4 5
Probability 0.48 0.38 0.08 0.05 0.01


a) What percent of the sons reached the highest class? 0.01
b) Check that this distribution meets the requirements of a discrete probability distribution.
c) What is P(X < 2)? 0.48
d) What is P(X = 2)?0.38 or 38%
e) Write the event: a son of a lower-class father attains one of the highest two social classes in terms of X. (6 points) P(X>4)=(PX=4)=P(X-5)
0.05=0.01=0.06

Answer 1

for part a)
it should be 1%

Answer 2

0.01 means 1% okay ?

Answer 3

ok

Answer 4

wat about part b ?

Answer 5

u have done a similar thing in ur previous problem

Answer 6

0.48+0.38+0.08+0.05+0.01=1

Answer 7

Its satisfies the 2 requirements

Answer 8

yup !

Answer 9

part c is right !

Answer 10

part d is also right

Answer 11

for part e) :

P(X >= 4) = P(X = 4) + P(X = 5)
= 0.05 + 0.01
= 0.06