Finding the Fourth Proportional to 1,109.89, 1,531.54 and 612.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.89 : 1,531.54 = 612.55 : x
2. Step 2: Convert to fraction form
   1,109.89/1,531.54 = 612.55/x
3. Step 3: Cross multiply
   1,109.89x = 1,531.54 × 612.55
4. Step 4: Simplify right side
   1,109.89x = 938,144.83
5. Step 5: Solve for x
   x = 938,144.83/1,109.89
6. Step 6: Final answer
   x = 845.26