Question 5 (a) Christina bought a graphical calculator for RM 800. After 3 years, the price of her graphical calculator depreciated to RM 600. (1) Find the equation that satisfy the above information where the value of graphical calculator is dependent on its age. (5 marks) (ii) Determine the value of the graphical calculator at the end of 4th year. (2 marks) (iii) Find the age of the graphical calculator when it has no value. (2 marks) (iv) Interpret the slope and the y-intercept of the equation found in question 5(a)(i). (4 marks) (b) An investment agent intends to use moving average to observe the trend of one of his stock. He obtained the share price of his stock for the past 7 months, from JAN 2021 to JULY 2021 as stated in the table below. JAN FEB MAR APR MAY JUN JUL Month 2021 2021 2021 2021 2021 2021 2021 Share price (RM/unit) 1.52 1.60 2.10 2.32 2.90 2.38 2.65 (1) Use a 3-months moving average of the share price to forecast for the month of MAY 2021 and find the forecast error. (Please round the forecasted figures to 2 decimal places). (3 marks) (ii) Use a 5-months moving average of the share price to forecast for the month of JUN 2021 and find the forecast error. (Please round the forecasted figures to 2 decimal places). (4 marks)