Finding the Fourth Proportional to 1,109.90, 1,662.12 and 561.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.90 : 1,662.12 = 561.33 : x
2. Step 2: Convert to fraction form
   1,109.90/1,662.12 = 561.33/x
3. Step 3: Cross multiply
   1,109.90x = 1,662.12 × 561.33
4. Step 4: Simplify right side
   1,109.90x = 932,997.82
5. Step 5: Solve for x
   x = 932,997.82/1,109.90
6. Step 6: Final answer
   x = 840.61