When fastening a heavy item to brick, what is the most important step?

Dr. dow jones wants to know whether a problem-based approach to teaching economics will result in higher academic performance than his traditional method. of the six sections of economics 101 at his university, dr. jones randomly assigns three sections to the traditional method and three sections to the problem-based method for unit 1 of the course. then all sections switch the instructional method for unit 2. he plans to compare the performance of the two groups of sections on their unit 1 and unit 2 exams. this study employs a design.

Quick computing currently sells 12 million computer chips each year at a price of $19 per chip. it is about to introduce a new chip, and it forecasts annual sales of 22 million of these improved chips at a price of $24 each. however, demand for the old chip will decrease, and sales of the old chip are expected to fall to 6 million per year. the old chips cost $10 each to manufacture, and the new ones will cost $14 each. what is the proper cash flow to use to evaluate the present value of the introduction of the new chip? (enter your answer in millions.)

Ahospital purchases a $500,000 magnetic resonance imaging (mri) machine that has a useful life of 9 years. the salvage value at the end of 9 years is $77,000. (a) write a linear equation that describes the value y (in dollars) of the mri machine in terms of the time t (in years), 0 ≤ t ≤ 9. (b) find the value, in dollars, of the machine after 6 years. $ (c) find the time, in years, when the value of the equipment will be $140,000. (round your answer to two decimal places.) yr