In a transposition experiment discussed in class, chimpanzees were reinforced for choosing a medium gray card over a light gray card. Then, in Phase 2, they were given a choice between medium gray and dark gray. In the second phase, the cognitive view was that the animals would choose the gray card based on the concept of learning:

This schedule shows the opportunity cost of producing doughnuts, bagels, and croissants. refer to the schedule and use the drop-down menu to answer each question. on day 2, raj makes 70 more bagels than on day 1. what is the opportunity cost of producing 70 more bagels? on day 3, raj makes 50 more croissants than on day 2. what is the opportunity cost of producing fifty more croissants?

The owner of a one-acre parcel of land with a small house on it rented the property to a professor of a nearby college at a monthly rental of $500. several years later, after the professor got tenure, the parties orally agreed that the professor would purchase the property from the owner for the sum of $60,000, payable at the rate of $500 a month for 10 years. they agreed that the owner would give the professor a deed to the property after five years had passed and $30,000 had been paid toward the purchase price, and that the professor would execute a note secured by a mortgage for the balance. the professor continued in possession of the property and made all monthly payments in a timely fashion. when he had paid $30,000, he tendered a proper note and mortgage to the property owner and demanded that she deliver the deed as agreed. the owner refused because valuable minerals had been discovered on adjacent parcels in recent months, causing the value of this parcel of land to increase to 10 times its former value. the professor brought suit against the property owner for specific performance. if the court rules in favor of the property owner, what is the likely reason?

Read the aphorisms. be slow in choosing a friend, slower in changing. an open foe may prove a curse; but a pretended friend is worse. a true friend is the best possession. according to these aphorisms from benjamin franklin's poor richard's almanack, what might happen if a person is careless in choosing a friend? it is best not to have friends because they will usually betray you. casual friends are often the best and can be more trusted than enemies. a person who has betrayed you can sometimes become a good friend. a friend who is not carefully chosen can be worse than an enemy.