Finding the Fourth Proportional to 1,140.84, 1,574.20 and 668.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,140.84 : 1,574.20 = 668.72 : x
2. Step 2: Convert to fraction form
   1,140.84/1,574.20 = 668.72/x
3. Step 3: Cross multiply
   1,140.84x = 1,574.20 × 668.72
4. Step 4: Simplify right side
   1,140.84x = 1,052,699.02
5. Step 5: Solve for x
   x = 1,052,699.02/1,140.84
6. Step 6: Final answer
   x = 922.74