Finding the Fourth Proportional to 1,111.15, 1,532.77 and 668.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.15 : 1,532.77 = 668.78 : x
2. Step 2: Convert to fraction form
   1,111.15/1,532.77 = 668.78/x
3. Step 3: Cross multiply
   1,111.15x = 1,532.77 × 668.78
4. Step 4: Simplify right side
   1,111.15x = 1,025,085.92
5. Step 5: Solve for x
   x = 1,025,085.92/1,111.15
6. Step 6: Final answer
   x = 922.55