This recipe does not have any standard fermentables, i.e. just the apple juice, so the equivalent weight and PPG for the juice can be worked out by taking the actual OG of the juice and then using the following formulas.
Since SG refers to the density of a liquid, with respect to water, you can convert volume to lbs and sg to ppg with the following two formulas.
Weight = 8.34* V * SG, where V is the volume in gallons, and SG is the gravity reading.
e.g. 44 lbs = 8.34 * 5 * 1.055.
Similarly, the PPG conversion is.
PPG = (SG - 1)*1000 V / weight
e.g. 6.251 = (1.055 - 1)* 1000 5 / 44