Sophie is stuffing envelopes for a marketing firm. She receives $1.00 for every 50 envelopes she stuffs. Based on what is known about schedules of reinforcement, you should conclude that Sophie's envelope stuffing is reinforced on:

With a known population mean of 1500, and a known standard error of the

mean of 42.50, what is the probability of selecting at random a sample whose mean is 1450 or less? What will be an ideal response?

According to the cognitive perspective, at what age will a child develop specific attachments?

a. 6-7 months b. 4-5 months c. 3-4 months d. 1-2 months