These are data for job vacancies in the mining industry in Australia for the period November 2015 to May 2020. Use the data to answer the following questions.

(a) Compute a 4-period MA to forecast job vacancies for the given period.

(b) Compute a 4-year weighted MA to forecast job vacancies for the given period. Weight the most recent period by 4, the next most recent period by 3, the next period by 2 and the last period of the four by 1.

(c) Determine the errors for parts (a) and (b). Compute the MSE for parts (a) and (b). Compare the MSE values and then comment on the effectiveness of the MA versus the weighted MA for these data.

Period ....................................... Job vacancies (’000s)
Nov. 15 ............................................ 4.1
Feb. 16 ............................................ 5.2
May 16 ............................................ 6.2
Aug. 16 ............................................ 7.1
Nov. 16 ............................................ 7.7
Feb. 17 ............................................ 8.1
May 17 ............................................ 9.5
Aug. 17 ............................................ 9.9
Nov. 17 .......................................... 10.3
Feb. 18 ............................................ 9.9
May 18 ............................................ 9.6
Aug. 18 ............................................ 8.0
Nov. 18 ............................................ 8.3
Feb. 19 ............................................ 6.7
May 19 ............................................ 5.1
Aug. 19 ............................................ 4.9
Nov. 19 ............................................ 4.7
Feb. 20 ............................................ 5.0
May 20 ............................................ 4.2