A profesor decides to run an experiment to measure the effect of time pressure on final exam scores. He gives each of 400 students in his course the same final exam, but some students have 90 minutes to complete the exam, while others have 120 minutes. Each student is randomly assigned one of the examination times based on the flip of a coin. Let Yi denote the number of points scored on the exam by the ith student ( 0 less than or equl to Yi less than or equal to 100), let Xi denote the amount of time that the student has to complete the exam (Xi = 90 or 120), and consider the regression model Yi = β0 + β1Xi + ui,

E(ui) = 0 Which of the following are true about the unobservable ui?

a. there is no way to calculate it
b. ui represents factors other than time that influence the student's performance on the exam.
c. ui will be zero for all students because time spent studying is likely the only factor that affects exam performance.

Label each scenario with the term that best describes it. use the midpoint method when applicable. marcel duchamp was a famous artist prior to his death, and was known for his dada artwork, including works such as "soft toilet". all of his original sculptures and paintings go on sale. paul owns a tim horton's, a famous donut and coffee franchise. he is willing to sell as many maple glazed donuts as customers want at a price of $1.00 each, but he refuses to sell any donuts for any price lower than $1.00 . the price of facial tissues rises from $2.85 per box to $3.15 . as a result, p& g increases production from 15 million boxes to 25 million boxes of facial tissue. with the school semester starting for both high school and college, papermate chooses to increase production of pens from 38 million to 42 million after global prices of writing instruments increase from $1.90 a package to $2.10 a package. bright ideas increases its production of lightbulbs by 15% after a 400% increase in the price of fluorescent bulbs.labels: elastic supply; perfectly inelastic supply; perfectly elastic supply; inelastic supply; unit-elastic supply.

Florence invested in a factory requiring. federally-mandated reductions in carbon emissions. how will this impact florence as the factory's owner? a. her factory will be worth less once the upgrades are complete. b. her factory will likely be bought by the epa. c. florence will have to invest a large amount of capital to update the factory for little financial gain. d. florence will have to invest a large amount of capital to update the factory for a large financial gain.

From what part of income should someone take savings?