Finding the Fourth Proportional to 1,150.55, 1,725.82 and 420.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,150.55 : 1,725.82 = 420.12 : x
2. Step 2: Convert to fraction form
   1,150.55/1,725.82 = 420.12/x
3. Step 3: Cross multiply
   1,150.55x = 1,725.82 × 420.12
4. Step 4: Simplify right side
   1,150.55x = 725,049.40
5. Step 5: Solve for x
   x = 725,049.40/1,150.55
6. Step 6: Final answer
   x = 630.17