4. The following table contains information on disposable income (Yd) and consumption (C) for the country of Makmur. Disposable Income Consumption: C - 100 + MPC (Yd) (millions of RM) (millions of RM) 800 820 900 910 1,000 1,000 1,100 1,090 1,200 1,180 a. Calculate the MPC and construct the savings function (S). What is the value of savings at the level of disposable income of RM1,200 million? b. Explain the MPC that you obtained in question (a) and why autonomous consumption is negative in savings