Univariate linear regression Note: Solutions to this problem must follow the method described in class and the linear regression handout. There is some flexibility in how your solution is coded, but you may not use special functions that automatically perform linear regression for you. Load in the BodyBrain Weight. csv dataset. Perform linear regression using two different models: M1: brain_weight = w0 + w1 x body_weight M2: brain_weight = w0 + w1 x body_weight + w2 x body_weight2
a. For each model, follow the steps shown in class to solve for w. Report the model, including w values and variable names for both models.
b. Use subplots to display two graphs, one for each model. In each graph, include: • Labeled x and y axes • Title • Scatterplot of the dataset • A smooth line representing the model
c. For each model, calculate the sum squared error (SSE). Show your 2 SSE values together in a bar plot.
d. Which model do you think is better? Why? Is there a different model that you think would better represent the data?
Body weight (kg) Brain weight (g)
0.023 0.4
0.048 0.33
0.075 1.2
0.12 1
0.122 3
0.2 5
0.28 1.9
0.55 2.4
0.75 12.3
0.785 3.5
0.93 3.5
1.04 5.5
1.35 8.1
1.41 17.5
2.5 12.1
3 25
3.3 25.6
3.6 21
4.288 39.2
5.3 41.6
6.8 179
10 115
10.55 179.5
27.66 115
35 56
36.33 119.5
52.16 440
55.5 175
60 81
62 1320
85 325
93 225
100 157
110 288
110 442
187.1 419
192 180
207 406
250 334
465 423
480 712
521 655
529 680
1400 590
2547 4603
6654 5712

Write a method named addall that could be placed inside the hashintset class. this method accepts another hashintset as a parameter and adds all elements from that set into the current set, if they are not already present. for example, if a set s1 contains [1, 2, 3] and another set s2 contains [1, 7, 3, 9], the call of s1.addall(s2); would change s1 to store [1, 2, 3, 7, 9] in some order. you are allowed to call methods on your set and/or the other set. do not modify the set passed in. this method should run in o(n) time where n is the number of elements in the parameter set passed in.

Afiling system in which an intermediary source of reference, such as a file card, must be consulted to locate specific files is called a(n) system. a. shelf filing b. direct filing c. indirect filing d. shingling

Computer security/cybersecurity1) each of the following code fragments contains a number of security vulnerabilities. for each fragment, identify these security vulnerabilities and, for each vulnerability, discuss at least one way that it could be improved. note that in your discussion of how each vulnerability could be improved, you do not need to re-write a new version of the program in c; simply discuss your solution, either in pseudocode or in 1-2 sentences.a) /* file descriptor leak */#include #include int main(int argc, char *argv[]){ char *filepath = argv[0]; char *shellpath = argv[1]; file *passwords; passwords = fopen(filepath, "r"); /* read the password and do something with it */ /* . . */ /* fork and execute alternative shell */ execl(shellpath, "shell", null); }b)#include /* assume the following function is written for an electronic storefront. the user will enter the id of the item to be ordered, as well as the quantity of units that they would like to purchase. the program will then lookup the price for the price for the item using a predefined function, and return the total cost of the order.*/int gettotalcost(){ char itemid[9]; int price, unitsordered, cost; printf(" enter the 9-digit id of the item to be ordered: "); scanf("%s", & itemid); /* lookup the price according to the itemid */ price = getpricebyid(itemid); printf(" enter the quantity of units to be ordered: "); scanf("%d", & unitsordered); cost = price * unitsordered; return cost; }c)#include /* the following function is intended to return a user's full name by concatenating the user's first and last name into a single string and then returning that string. */char *getfullname(char *firstname, char *lastname, int max_len){ char fullname[max_len]; strcpy(fullname, firstname); strcat(fullname, " "); strcat(fullname, lastname); return fullname; }d)#include /* the following code snippet runs through the list of cli arguments entered and displays them to the console. */int main(int argc, char *argv[]){ int i; printf("you've entered the following arguments: "); for(i = 0; i < argc; i++){ print(argv[i]); printf("\n"); } /* */}