PROBLEM:

Time Series data on Fiji's Consumer Price Index (CPI) between 2017 - 2020 sourced from the Fiji Bureau of Statistics (FBoS). We are going to use the sheet called "ECN803 Data" which have been transposed from CPI tables produced by FBoS.

Using this data, please answer the following questions:

1. Using the ratio to moving average (MA), calculate the seasonally adjusted indices for each quarter beginning Q1, 2017

2. Establish a regression trend line in the form of Y = a + bX + by estimating the values for 'a' and 'b'.

3. Using the trend line in (2), calculate a seasonally adjusted trend estimate for Q2, 2020

4. What would be your forecasted Consumer Price Index for all goods and services in Q1, Q2, Q3 and Q4 in 2021?

Instructions:

(i) https://www.youtube.com/watch?v=HIWXdHlDSFs (ii) https://www.youtube.com/watch?v=Aw77aMLj9uM

a table to show how the trend line in Question 2 is derived; for example, your X, Y, XY as in the formula for calculating the two parameters "a' and 'b" in simple regression equation.

The use of excel spreadsheet is encouraged and forecasting techniques using time series data. However, I will accept manual calculations if you are not comfortable using excel. The same detail analysis, however, is expected in both methods.

ECN 803 data

Table 1
CONSUMER PRICE INDEX: NATIONAL
PERCENTAGE CHANGE ON CORRESPONDING PERIOD IN PREVIOUS YEAR
			Food and Non-alcoholic Beverages	Alcoholic Beverages, Tobacco and Narcotics	Clothing and Footwear	Housing, Water, Elec., Gas and Other Fuels	Furnishings, Hhld Equip. & Routine Hhld Maint.	Health	Transport	Commun-ication	Recreation & Culture	Education	Restaurants & Hotels	Miscella-neous Goods & Services
Division
		All
		Items
Weight		1000.0	347.1	105.7	21.7	126.8	50.0	14.1	138.7	44.2	16.1	75.3	29.8	30.5
Annual	2015	1.4	4.8	9.8	2.1	-4.5	0.4	2.8	-3.7	0.1	0.6	-1.7	1.5	4.1
Average	2016	3.8	5.9	27.0	1.2	-5.0	-0.5	4.1	-3.9	-1.5	-1.6	8.2	3.5	-0.8
	2017	3.3	-2.1	31.8	0.2	2.0	0.8	-0.4	1.8	-0.3	-0.4	0.7	2.9	-0.6
	2018	4.1	3.4	19.4	0.6	2.1	-0.2	-1.3	2.0	0.1	0.2	0.0	1.6	0.0
	2019	1.8	4.9	5.5	1.0	-0.1	0.9	-0.4	0.1	-13.8	0.2	4.8	0.2	1.4
2017	January	6.8	7.1	41.4	1.3	-0.6	1.4	-0.4	0.4	-0.3	-0.2	9.0	2.5	-0.8
	February	5.5	4.3	42.9	1.3	-0.6	2.8	-0.3	0.4	-0.2	0.1	0.0	2.7	-0.4
	March	5.6	3.1	48.4	2.0	-0.6	3.4	0.1	0.3	-0.3	0.0	0.0	2.8	-0.6
	April	4.1	-3.5	44.2	-0.4	4.5	2.2	0.5	3.4	-0.3	0.0	0.0	2.8	-0.5
	May	2.5	-4.8	28.9	-0.6	4.5	0.4	0.4	3.2	-0.3	-0.2	0.0	2.8	-0.2
	June	2.0	-6.0	25.8	-0.3	4.5	0.1	-1.3	3.3	-0.3	-0.4	0.0	2.2	-0.3
	July	2.0	-6.2	30.5	-0.3	2.2	0.4	-1.3	1.8	-0.3	-2.1	0.0	3.3	-0.4
	August	2.0	-5.2	27.8	-0.8	1.9	0.5	-1.2	1.8	-0.3	-1.0	0.0	3.3	-0.5
	September	2.1	-4.2	23.6	-0.1	1.9	0.4	-1.2	1.9	-0.3	-1.1	0.0	2.9	-0.8
	October	2.6	-3.7	27.5	-0.9	2.2	-0.3	-0.7	2.0	-0.3	-0.6	0.0	2.9	-0.9
	November	2.5	-3.0	25.4	0.9	2.2	-0.5	-0.6	2.0	-0.2	-0.3	0.0	2.9	-0.9
	December	2.8	-2.8	26.1	0.7	2.2	-0.9	0.6	1.8	-0.2	0.4	0.0	3.0	-1.0
2018	January	1.6	-6.0	23.5	0.4	2.9	-1.5	2.0	1.5	0.0	0.5	0.0	1.6	-0.6
	February	2.3	-2.0	21.4	0.5	2.9	-1.7	-0.7	1.4	0.1	0.2	0.0	2.4	-0.4
	March	2.6	0.2	16.4	0.2	2.9	-1.9	0.0	1.4	0.1	0.1	0.0	2.3	0.0
	April	4.0	6.1	17.2	0.2	0.1	-1.7	-0.9	0.5	0.1	0.2	0.0	2.3	0.0
	May	5.1	6.4	23.3	0.5	0.1	-0.4	-0.7	0.7	0.1	0.2	0.0	2.3	-0.5
	June	4.6	5.1	22.3	0.6	0.1	-0.1	-1.3	0.7	0.1	0.2	0.0	2.2	-0.3
	July	4.7	4.1	21.6	0.4	2.3	-0.1	-2.4	2.4	0.1	0.4	0.0	1.1	0.0
	August	4.3	3.3	20.3	1.4	2.3	0.2	-2.3	2.4	0.1	0.3	0.0	1.1	0.1
	September	4.6	4.9	18.6	0.9	2.3	0.2	-2.3	2.4	0.1	0.4	0.0	1.1	0.3
	October	5.2	7.8	16.1	1.5	2.6	1.0	-2.3	3.3	0.1	0.4	0.0	1.1	0.3
	November	5.1	7.2	16.6	0.2	2.6	0.7	-2.1	3.3	0.1	0.3	0.0	1.1	0.5
	December	4.8	5.1	17.2	0.2	3.7	2.0	-2.2	3.4	0.1	0.2	0.0	0.8	0.7
2019	January	5.1	7.9	17.6	0.7	0.4	1.5	-3.1	0.8	0.1	0.4	0.0	0.2	0.6
	February	5.1	10.4	16.1	0.1	0.4	1.6	-1.1	0.9	-15.2	0.3	5.2	-0.6	0.5
	March	4.0	7.7	14.4	0.4	0.4	1.4	-2.0	0.9	-15.2	0.4	5.2	-0.1	0.3
	April	2.1	2.0	13.1	0.5	0.3	1.7	-1.2	-0.3	-15.2	0.4	5.2	-0.1	0.0
	May	2.1	4.7	8.0	0.7	0.3	0.7	-1.2	-0.2	-15.2	0.2	5.2	0.2	0.0
	June	2.8	7.3	7.8	0.9	0.3	0.7	-0.1	-0.2	-15.2	0.0	5.2	0.3	0.2
	July	0.7	3.2	2.1	0.8	0.1	0.8	0.8	0.3	-15.0	0.0	5.2	0.3	0.8
	August	1.2	5.6	0.8	1.1	0.1	0.5	0.8	0.4	-15.0	0.0	5.2	0.3	1.1
	September	0.4	3.3	0.0	1.6	0.1	0.7	0.9	0.4	-15.0	0.0	5.2	0.3	1.8
	October	-0.9	1.2	-2.3	1.4	-1.5	0.7	0.9	-0.9	-15.0	-0.1	5.2	0.3	2.8
	November	-0.3	2.9	-2.6	1.7	-1.5	1.0	0.5	0.0	-15.0	0.1	5.2	0.3	3.7
	December	-0.9	2.8	-4.3	1.9	-1.9	0.0	0.1	-0.5	-15.0	0.0	5.2	0.9	3.7
2020	January	-1.9	-1.4	-5.6	1.3	-1.2	0.2	0.1	1.1	-15.0	0.0	5.2	1.9	4.5
	February	-3.0	-6.1	-8.1	2.4	-0.5	-0.3	0.0	4.4	0.2	0.0	0.0	1.9	4.9
	March	-2.8	-5.6	-7.8	1.8	-0.5	0.1	0.6	4.1	0.1	-0.1	0.0	1.4	4.5
	April	-1.3	-1.0	-7.5	1.8	0.3	0.7	0.8	3.4	0.1	0.0	0.0	1.2	4.8
	May	-1.7	-1.0	-8.7	1.0	-0.9	3.5	0.3	0.9	0.4	-0.4	0.0	0.9	5.4