Finding the Fourth Proportional to 1,111.10, 1,533.09 and 668.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.10 : 1,533.09 = 668.90 : x
2. Step 2: Convert to fraction form
   1,111.10/1,533.09 = 668.90/x
3. Step 3: Cross multiply
   1,111.10x = 1,533.09 × 668.90
4. Step 4: Simplify right side
   1,111.10x = 1,025,483.90
5. Step 5: Solve for x
   x = 1,025,483.90/1,111.10
6. Step 6: Final answer
   x = 922.94