Finding the Fourth Proportional to 1,109.85, 1,531.58 and 612.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.85 : 1,531.58 = 612.50 : x
2. Step 2: Convert to fraction form
   1,109.85/1,531.58 = 612.50/x
3. Step 3: Cross multiply
   1,109.85x = 1,531.58 × 612.50
4. Step 4: Simplify right side
   1,109.85x = 938,082.03
5. Step 5: Solve for x
   x = 938,082.03/1,109.85
6. Step 6: Final answer
   x = 845.23