Question 4 1 pts Solving the identification problem means: Our r-squared is greater than 75 We run regression models with the right specification. We have a big enough n. We figure out a way to determine if two variables are causally linked or just correlated. We rule out the possibility that some third factor Cis causing both A and B. Question 5 1 pts Which of the following is not an observational study? An article in the Journal of Finance gets medical records for CEO's S&P 500 listed forms and notes that CEO's have higher testosterone and greater rates of male pattern baldness. Pfizer tests its vaccine by randomly assigning it to 500 out of 1000 study participants. I get data on foster youth and note that foster youth with an incarcerated father are more likely to arrested prior to age 18 than foster youth with deceased fathers. The Journal of Human Resources finds that job applicants with an undergraduate degree from Harvard or Stanford have higher starting salaries that job applicants who graduated from Penn. The Framingham Heart Study follows study participants from 1971 until they die and finds that those that drink coffee live shorter lives than those that do not drink coffee