Finding the Fourth Proportional to 1,109.40, 1,662.16 and 621.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.40 : 1,662.16 = 621.24 : x
2. Step 2: Convert to fraction form
   1,109.40/1,662.16 = 621.24/x
3. Step 3: Cross multiply
   1,109.40x = 1,662.16 × 621.24
4. Step 4: Simplify right side
   1,109.40x = 1,032,600.28
5. Step 5: Solve for x
   x = 1,032,600.28/1,109.40
6. Step 6: Final answer
   x = 930.77