Question

The following table shows the production of pig-iron and ferroalloys ('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

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

Step 1: Calculate 5-year moving totals and averages

1. 1974 - 1978 

M.A. = `(0 + 4 + 9 + 9 + 8)/5` 

= `30/5`

= 6

2. 1975 - 1979

M.A. = `(4 + 9 + 9 + 8 + 5)/5`

= `35/5`

= 7

3. 1976 - 1980

M.A. = `(9 + 9 + 8 + 5 + 4)/5`

= `35/5`

= 7

4. 1977 - 1981

M.A. = `(9 + 8 + 5 + 4 + 8)/5`

= `34/5`

= 6.8

5. 1978 - 1982

M.A. = `(8 + 5 + 4 + 8 + 10)/5`

= `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.