- A regression equation models the relationship between hours studied and test scores as: TestScore = 65 + 2.5(HoursStudied) + Īµ. Which of the following would indicate a source of bias in the estimated effect of hours studied on test scores? (Select all that apply)
- Students whose last name ended in the letter āSā were accidentally given 2 more points in the test
- Students who study more also have access to better tutoring programs
- Random noise in test-taking conditions
- Students who study more hours tend to be more motivated in general
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- Which of the following is an assumption necessary for a simple mean comparison to recover the causal effect?
- The mean of the treatment group must equal the mean of the control group
- The outcomes of the control group would be the same as the outcomes of the treatment group, had they received the treatment
- Same sizes need to be the same between treatment and control
- The difference in means should be economically significant
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- Imagine we have the following model: Hospitalized=Ī± + Ī²Vaccinated + Ļµ. In this situation, what would Corr(Vaccinated, Īµ)ā 0 imply?
- The effect of vaccination on outcomes is causal
- Vaccination is correlated with other factors affecting COVID-19 hospitalization rates
- The mean of the error term is non-zero
- That the variable vaccinations is a constant
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- There is a promising new white noise machine that has been shown to help increase the hours people sleep. The developers of this product want to grow sales, but an investor is concerned that people who bought this machine may also be more likely to use other sleep aids, like melatonin, also influencing their amount of sleep. Which of the following regressions would allow the concerned investor to understand if the machine is making a difference? The following multiple-choice options contain math elements, so you may need to read them in your screen reader's āreadingā or ābrowseā mode instead of āformsā or āfocusā mode.
- Sleep = Ī± + Ī²Machine + Ī³Melatonin + Ļµ
- Sleep = Ī± + Ī²Machine + Ļµ
- Machine = Ī± + Ī²Melatonin + Ļµ
- Machine = Ī± + Ī²Sleep + Ļµ
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