Finding the Fourth Proportional to 1,225.83, 1,691.61 and 666.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,225.83 : 1,691.61 = 666.29 : x
2. Step 2: Convert to fraction form
   1,225.83/1,691.61 = 666.29/x
3. Step 3: Cross multiply
   1,225.83x = 1,691.61 × 666.29
4. Step 4: Simplify right side
   1,225.83x = 1,127,098.79
5. Step 5: Solve for x
   x = 1,127,098.79/1,225.83
6. Step 6: Final answer
   x = 919.46