"Look at the following code. Which line will cause a compiler error? Line 1 public class ClassA
Line 2 {
Line 3 public ClassA() {}
Line 4 public final int method1(int a){ return a;}
Line 5 public double method2(int b){ return b;}
Line 6 }
Line 7 public ClassB extends ClassA
Line 8 { Line 9 public ClassB(){}
Line 10 public int method1(int b){ return b;}
Line 11 public double method2(double c){ return c;}
Line 12 }"

a. Line 4
b. Line 5
c. Line 10
d. Line 11

Using least squares fitting, you are to fit the data sets to the following models and solve for the parameters ai , where i is the index of the parameter. the input/output data for the systems are linked in the bblearn site. for each of the systems use matlab to plot the supplied data vs. the model fit on one plot. include your code in the solutions. (a) linear fit "lineardata.mat" y=a1x^3 + a2x^2 + a3x + a4 (b) plant fit "plantdata.mat g(s) = a1/(s + a2)

Assume that there is a 4% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on three independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?

File account.java (see previous exercise) contains a definition for a simple bank account class with methods to withdraw, deposit, get the balance and account number, and return a string representation. note that the constructor for this class creates a random account number. save this class to your directory and study it to see how it works. then write the following additional code: 1. suppose the bank wants to keep track of how many accounts exist. a. declare a private static integer variable numaccounts to hold this value. like all instance and static variables, it will be initialized (to 0, since it’s an int) automatically. b. add code to the constructor to increment this variable every time an account is created. c. add a static method getnumaccounts that returns the total number of accounts. think about why this method should be static - its information is not related to any particular account. d. file testaccounts1.java contains a simple program that creates the specified number of bank accounts then uses the getnumaccounts method to find how many accounts were created. save it to your directory, then use it to test your modified account class.