Finding the Fourth Proportional to 1,109.34, 1,662.80 and 561.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.34 : 1,662.80 = 561.78 : x
2. Step 2: Convert to fraction form
   1,109.34/1,662.80 = 561.78/x
3. Step 3: Cross multiply
   1,109.34x = 1,662.80 × 561.78
4. Step 4: Simplify right side
   1,109.34x = 934,124.98
5. Step 5: Solve for x
   x = 934,124.98/1,109.34
6. Step 6: Final answer
   x = 842.05