Finding the Fourth Proportional to 1,109.31, 1,663.59 and 561.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.31 : 1,663.59 = 561.15 : x
2. Step 2: Convert to fraction form
   1,109.31/1,663.59 = 561.15/x
3. Step 3: Cross multiply
   1,109.31x = 1,663.59 × 561.15
4. Step 4: Simplify right side
   1,109.31x = 933,523.53
5. Step 5: Solve for x
   x = 933,523.53/1,109.31
6. Step 6: Final answer
   x = 841.54