Two components X and Y are used as follows:

Normal usage

50 units each per week

Minimum usage

25 units each per week

Maximum usage

75 units each per week

Re order quantity

X: 400 units; Y: 600 units

Re order period

X: 4 to 6 weeks; Y: 2 to 4 weeks.

Calculate for each components: (1) the re order level, (2) the minimum level, (3) the maximum level, and (4) the average stock level.