Finding the Fourth Proportional to 1,054.72, 1,455.52 and 612.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,054.72 : 1,455.52 = 612.90 : x
2. Step 2: Convert to fraction form
   1,054.72/1,455.52 = 612.90/x
3. Step 3: Cross multiply
   1,054.72x = 1,455.52 × 612.90
4. Step 4: Simplify right side
   1,054.72x = 892,088.21
5. Step 5: Solve for x
   x = 892,088.21/1,054.72
6. Step 6: Final answer
   x = 845.81