Finding the Fourth Proportional to 1,112.89, 1,669.18 and 612.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,112.89 : 1,669.18 = 612.72 : x
2. Step 2: Convert to fraction form
   1,112.89/1,669.18 = 612.72/x
3. Step 3: Cross multiply
   1,112.89x = 1,669.18 × 612.72
4. Step 4: Simplify right side
   1,112.89x = 1,022,739.97
5. Step 5: Solve for x
   x = 1,022,739.97/1,112.89
6. Step 6: Final answer
   x = 918.99