In the alter, aronson, darley, rodriguez, and ruble experiment, black children who were asked to report their race prior to taking a test performed more poorly than children not reporting their race, because: a. the question removed a stereotype threat b. the question created a stereotype threat c. the children interpreted the instructions for the test as a challenge d. the children in the second part of the experiment were less intelligent than the children in the first part of the experiment

David consumes two things: gasoline (g) and bread (b). david's utility function is u(g, b) = 10g^0.25 b^0.75. use the lagrange technique to solve for david's optimal choices of gasoline and bread as a function of the price of gasoline, p_g, the price of bread, p_b, and his income m. with recent decrease in the price of gasoline (maybe due to external shock such as shale gas production) does david increase his consumption of gasoline? for david, how does partial differential g/partial differential p_g depend on his income m? that is, how does david's change in gasoline consumption due to an increase in the price of gasoline depend on his income level? to answer these questions, find the cross-partial derivative, |partial differential^2 g/partial differential m partial differential p_g.