Question

Three professors at George Washington University did an experiment to determine if economists are more selfish than other people. They dropped 122 stamped, addressed envelopes with $20 cash in two different classrooms (one economics, one not) on the George Washington campus. Of these, 42% were returned overall. From the economics class 51% of the envelopes were returned. From the other class 36% were returned.
From
the business, psychology, and history classes 31% were returned.
Let: R = money returned; E = economics classes; O = other classes
a. Write a probability statement for the overall percent of money returned.
b. Write a probability statement for the percent of money returned out of the economics classes.
c. Write a probability statement for the percent of money returned out of the other classes.
d. Is money being returned independent of the class? Justify your answer numerically and explain it.
e. Based upon this study, do you think that economists are more selfish than other people? Explain why or why not. Include numbers to justify your answer.

Answer 1

Solution :

It is given that :

At George Washington University, three professors wanted to do an experiment to find out if the economist people are more selfish than the other people.

They dropped 122 stamped addressed envelopes filled with 20 dollar cash at a economics classroom and the other at the other subjects classroom.

It is given that --

money returned = R

economics classes = E

other classes = O

a). the probability statement of the overall percent of the money returned is given by : 100.P(R)

b). the statement of probability that the percent of money returned out of the economics classes is 100.P(R|E)

c). the statement of probability that shows the percent of the money returned out of the other classes is 100.P(R|O)

d). No, the money returned is not independent of the classes as the P(R) is not equal to P(R|E)

e).  No, based on the study, the economist are not selfish than other classes' people as the percent of the envelops returned from the economics classes is 51% and that from other classes is 36%.