Do dogs pick up information by eavesdropping on interactions between people? Researchers in Argentina (Freidin, et al., 2013) wanted to see whether dogs would show a preference for people based on their cooperativeness toward others. A dog watched a man acting as a “beggar” approach two women in a room. The man would ask for food. One woman (the “positive” donor) would give the beggar a corn flake and the beggar would take it and say, ‘‘Qué rico!’’ (“So tasty!”). When the beggar approached the other woman (the “negative” donor) and asked for a corn flake, he would take it and put it back on the plate where it came from and say ‘‘Qué feo!’’ (“So ugly!”). The beggar would then leave the room. The dog, after watching all this, would be released and the researchers would see which donor the dog would approach first. Fifteen dogs were tested with this scenario and 13 of them approached the positive donor. 

a. Write out the hypotheses in symbols if we want to test whether dogs are more likely to approach the positive donor. 

b. Using the One Proportion applet, determine a standardized statistic for this test. Based on your standardized statistic do you have strong evidence that dogs are more likely to approach the positive donor? Explain how you are determining this. 

c. Using the One Proportion applet, determine a p-value for this test. Does your p-value back up your answer from part (b)? Explain how you are determining this.