Finding the Fourth Proportional to 1,056.72, 1,585.16 and 407.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,056.72 : 1,585.16 = 407.52 : x
2. Step 2: Convert to fraction form
   1,056.72/1,585.16 = 407.52/x
3. Step 3: Cross multiply
   1,056.72x = 1,585.16 × 407.52
4. Step 4: Simplify right side
   1,056.72x = 645,984.40
5. Step 5: Solve for x
   x = 645,984.40/1,056.72
6. Step 6: Final answer
   x = 611.31