2. (75 points+5 extra credit) For each of the code segments below, determine an equation for the worst-case computing time Tn) (expressed as a function of n, ie. 2n+4) and the order of magnitude (expressed using big O notation, i.e. O(n)) a Calculate mean sum0; cin >> x; while (x != -999) n++i sum += x; cin >> x; mean sumn 2. (continued) (75 points) For each of the code segments below, determine an equation for the worst-case computing timeTn) (expressed as a function of n, i.e. 2n+4) and the order of magnitude (expressed using big O notation, Le. O(n)) b. Matrix addition for (int i " 0; = 1) f. (extra credit-5 points) x1i for (int i " 1;