Question

The following table shows the production of pig-iron and ferro alloys ('000 metric tons)

Years	1974	1975	1976	1977	1978	1979	1980	1981	1982
Production	0	4	9	9	8	5	4	8	10

Find trend values for the above data by using 5 yearly moving averages.

Answer 1

Given:

Years	1974	1975	1976	1977	1978	1979	1980	1981	1982
Production	0	4	9	9	8	5	4	8	10

To find: Trend values by 5-year moving averages.

Step 1: Calculate 5-year moving totals and averages

⇒ 1974 – 1978 

Total = 0 + 4 + 9 + 9 + 8 = 30, M.A. = `30/5` = 6

⇒ (Trend for 1976) → 1975 – 1979

Total = 4 + 9 + 9 + 8 + 5 = 35, M.A. = `35/5` = 7

⇒ (Trend for 1977) → 1976 – 1980

Total = 9 + 9 + 8 + 5 + 4 = 35, M.A. = `35/5` = 7

⇒ (Trend for 1978) → 1977 – 1981

Total = 9 + 8 + 5 + 4 + 8 = 34, M.A. = `34/5` = 6.8

⇒ (Trend for 1979) → 1978–1982

Total  = 8 + 5 + 4 + 8 + 10 = 35, M.A. = `35/5` = 7

(Trend for 1980)

Step 2: Trend values (5-year moving averages)

Year	1976	1977	1978	1979	1980
Trend	6	7	7	6.8	7

Trend values are 6, 7, 7, 6.8, 7 for years 1976 to 1980.