Received
Date		No. of Units		Unit Cost		Issued, No. of Units		Balance, No. of Units
January 2		1,700		$4.74				1,700
7						1,200		500
10		1,100		5.06				1,600
13						1,000		600
18		1,500		5.21		800		1,300
20						1,100		200
23		1,800		5.37				2,000
26						1,300		700
28		2,100		5.53				2,800
31						1,800		1,000

Calculate the perpetual average cost (Moving)