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Based on the above binary logit model in Q9, the probability of buy (i.e., P(buy=1) in the city 3 (i.e., C(city)[T.3]=1, St. Louis) is (1)___________(a. higher, b. smaller; 1 points) than that of the base group (2)__________(a. Rolla,   b. Kansas City, c. St. Louis; 2 points) at statistically (3) _______________ (a. insignificant, b. significant 10%, c. significant 5%, d. significant 1%; 1 point).

Based on the above example of the decision tree (DT) for the binary classification (0: candy 1: wine), the predicted class in the terminal node  is (1)____________(a. candy, b. wine; 2 points), and the predicted class in the terminal node  is (2)____________(a. candy, b. wine; 2 points).

Decision Tree (DF) for classification selects a feature and threshold to split feature space in each node that minimize impurity measures. Please select the two impurity measures of DT for classification:_____________ 

Let’s assume that an economist wants to investigate consumer choices for an energy saving device as follows:

Decision Tree (DF) for regression selects a feature and threshold to split feature space in each node that minimize __________________ (one answer; 4 points).

Look at the distribution for this word problem and determine if X =100 is a score that is noticeably different from the mean.  In your answer indicate 1) yes or no 2) explain why you selected your answer (i.e., back up with reasoning from facts learned in this class). 

The economist in Q1 was concerned about the confounding effect on the treatment variable (i.e., prime_card variable); therefore, the economist applied the instrument variable (IV) method using two-stage least square regression (2SLS) to mitigate bias and get a consistent estimator for the treatment effect. In particular, randomly assigned eligibility of the prime membership card for consumers (i.e., ‘prime_elegible’) is used as an instrument variable (IV). we assume that ‘prime_elegible’ is a valid instrument variable (IV). Table 1 The empirical results from OLS Table 2 The empirical result from IV with 2SLS Based on the above Tables 1 and 2, the coefficient for the prime_card in OLS is (1)____________ (number, 1 point) and the coefficient of the prime_card (i.e., the predicted prime_card in the second stage) in 2SLS is (2)___________(number, 1 point). As a result, the OLS estimator may have (3)______________ (a. downward bias (i.e., underestimate), b. upward bias (i.e., overestimate); 2 points).      

These questions are related to design principles for secure systems. I. Consider a security screening setting like the one that is done at airports before travelers are allowed to board flights. Assume a certain airport uses the following screening protocols.1. Everyone, except those who are explicitly exempted, must undergo the security screening.2. All travelers go through the first screening stage. A subset of travelers are also flagged for a second screening.3. Once successfully screened, travelers only have access to the areas of the airport where their gates are located. What security design principle can be used to explain each of the above choices made for air travel security? Explain your answers. (2+2+2)II. The “Reflections on Trusting Trust” paper described a trojan in a compiler binary that could not be detected even if we had access to and examined the source of the compiler. We discussed how the defense-in-depth principle can help us detect if the trojan exists in a compiler by using two independently developed compilers when at least one of them is correct. We could determine if one of the compilers has the trojan but could not ascertain which one is malicious. To answer this question, the following idea is suggested. Instead of two, we will get three independently developed compilers such that no more than one could be malicious.1. If at least two of the compilers are good, can we use these three compilers to detect the bad one when one exists? (1 pts.)2. Explain your answer to question 2.1. More specifically, if your answer is no, explain why this is not possible. If the answer is yes, show how the bad compiler can be identified. (3 pts.)

Which of the following is the BEST example of how to use data from either an Electronic Medical Record (EMR) or an external report?

Please read the case of EMMA. Which of the following statements would be found in the BEHAVIOR portion of Emma’s evaluation report?