Suppose that the Dallas School District wants to achieve Six Sigma quality levels of performance in delivering students to school. They have established a 20-minute window as an acceptable range within which buses carrying students should arrive at school.

a. What is the maximum allowable standard deviation of arrival times required in order to achieve this standard of quality? (Round your answer to 2 decimal places.)
b. If they achieve this standard, about how many times out of a million deliveries will a bus deliver students either too early or too late? (Round your answer to 1 decimal place.)

Which of the following statements about revision is most accurate? (a) you must compose first drafts quickly (sprint writing) and return later for editing. (b) careful writers always revise as they write. (c) revision is required for only long and complex business documents. (d) some business writers prefer to compose first drafts quickly and revise later; others prefer to revise as they go.

Atrough in the business cycle occurs when

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.