A kg box is moving on a horizontal surface in the +x direction (toward the right). The coefficient of kinetic friction is . An unknown force F, parallel to the surface, is applied to the box. The velocity as a function of time is shown in the figure. Given t1 = s, t2 = s, v1 = m/s, and v3 = m/s, determine the magnitude of the force F during the time interval from t1 to t2. Express your answer in newtons.

Let’s assume that an economist wants to measure the effect of a prime membership card on consumers’ purchase volume. The economist collects the sample and runs the linear regressions as follows: ‘new_pv’: purchase volume of a consumer (dependent variable) ‘prime_card’ : prime card member (1) or not (0). – binary dummy variable ‘age’: age of a consumer ‘income’: income of a consumer ‘prime_card: income’: interaction terms between prime_card and income variables. Based on model 1, 1 year increase in age variable will (1) _______________ (a. increase, b. decrease; 2 points) consumer purchase volumes by (2) _______________ (number; 1 point) at statistically (3) _______________(a. insignificant, b. significant 10%, c. significant 5%, d. significant 1%; 1 point).

There are two binary logit models as ‘logit’ and ‘full_logit’ models. Based on the log-likelihood function (LL), the model fit of model 1 is (1)__________ (a. better b. worse; 2 points) than model 2. Based on Akaike Information Criterion(AIC), the model fit of the model 1 is (2)__________ (a. better b. worse; 2 points) than model 2.

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).

What z-score represents X = 110?  Use the mean and standard deviation you just calculated in the preceding questions to arrive at your answer.  

In terms of goodness of model-fit, (1)_______________ (a. model 1 b. model 2, c. model 3; 2 points) is the best model based on (2)_____________ (a. R-squared / b. Adjusted R-squared; 2 points).

Based on model 1, consumer purchase volume from prime member consumers (i.e., prime_card =1) is (1)_______________ (a. higher, b. smaller; 2 points) by (2) _______________ (number; 1 points) than that of non-prime card member consumers (i.e., prime_card =0; the base group) at statistically (3) _______________ (a. insignificant, b. significant 10%, c. significant 5%, d. significant 1%; 1 point).

A patient has been prescribed bisacodyl (Dulcolax) for constipation. This medication ___________________.

Identify which of the following orbital diagrams are for phosphorus.   

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.)