Question 3

(a) Given that A and B are two square matrices such that AB = 0. Show that if A is

invertible then B = 0.

(4 marks)

The table below shows the HDB resale price index for Q1 from year 2002 to 2022 (4

years interval)

(b)

(i)

(ii)

Year, t (20xx) HDB resale price index

69.1

73.6

112.1

143.5

131.4

159.5

02

06

10

14

18

22

Table Q3(b)

Use linear regression minimizing the SSE, obtain the linear function I(t) for

estimating the above data set.

(11 marks)

Plot both the data set and your prediction equation I(t) using a graph plotter.

Estimate the year that the price index will hit 200, assuming the trend stays

intact.

(5 marks)