On average, the merchandise shop sells 80 CDs per 1 vinyl record. This is our conversion factor. To estimate the number of vinyl records likely to be sold when 760 CDs have been sold we will use proportions.
760 CD × (1 vinyl record/ 80 CD) = 9.5 ≈ 10 (we round it off because you cannot sell half a vinyl record).
The merchandise shop sells 80 CDs for every 1 vinyl record. We have to find how many vinyl records they are likely to sell if the merchandise shop sells 760 CDs: 80 CDs -------------------- 1 vinyl record 760 CDs --------------------- x vinyl records --------------------------------------------------------- 80 : 760 = 1 : x 80 x = 760 x = 760 : 80 x = 9.5 or 9 ( we need a whole number ) Answer: They are likely to sell 9 vinyl records.
