Use the following information to answer the next two questions. An investigation reported in the November 2007 issue ofNature(Hamlin, Wynn, and Bloom) aimed at assessing whether infants take into account an individual's actions towards others in evaluating that individual as appealing or aversive, perhaps laying the foundation for social interaction. In one component of the study, each of sixteen 10-month-old healthy infants (in New England) were shown a "climber" character (a piece of wood with "google" eyes glued onto it) that could not make it up a hill in two tries. Then they were shown two scenarios for the climber's next try, one where the climber was pushed to the top of the hill by another character ("helper") and one where the climber was pushed back down the hill by another character ("hinderer"). Each infant was alternately shown these two scenarios many times. Then the child was presented with both pieces of wood (the "helper" and the "hinderer") and asked to pick one to play with. In the study 14 out of the 16 babies picked the "helper" toy. Does this provide evidence that such 10-month-old infants have agenuine preferencefor the helper toy?

1. Define the parameter of interest in the context of the study and assign a symbol to it.
2. State the null hypothesis and the alternative hypothesis using the symbol defined in part (a).
3. What is the observed proportion of times the infants picked the helper toy? What symbol should you use to represent this value?