Finding the Fourth Proportional to 1,200.78, 1,800.96 and 551.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.78 : 1,800.96 = 551.34 : x
2. Step 2: Convert to fraction form
   1,200.78/1,800.96 = 551.34/x
3. Step 3: Cross multiply
   1,200.78x = 1,800.96 × 551.34
4. Step 4: Simplify right side
   1,200.78x = 992,941.29
5. Step 5: Solve for x
   x = 992,941.29/1,200.78
6. Step 6: Final answer
   x = 826.91