The way we buy products using credit cards has changed in recent years. Originally the magnetic stripe on the back of the card was used with a signature. Then chip and PIN methods were
used, and more recently contactless methods have been introduced.
Discuss the effectiveness of using these different methods to improve security when paying
for goods.

Imagine that you have a friend who is starting a small business and is interested in using social media to spread the word. he is not certain that it is a good move, and has come to you for . would you advise him to use social media to advertise his business? why or why not? support you answer with information from the text.

Write a function that draws a pool ball. this function should take as parameters, the color, the number that should go on the pool ball, and the location of the center of the pool ball. the radius of the pool balls should be pool_ball_radius, and the font of the number should be pool_ball_font. the text of the pool ball font should be white. drawpoolball(color. orange, 5, 100, 100); drawpoolball(color. green, 6, 50, 200); drawpoolball(color. red, 3, 150, 350); drawpoolball(color. blue, 2, 250, 140); to center the numbers on the pool ball, you should use the getwidth() and getheight() methods. you are allowed to call these methods on your text object, such as txt.

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)