Finding the Fourth Proportional to 1,139.60, 1,572.48 and 667.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.60 : 1,572.48 = 667.46 : x
2. Step 2: Convert to fraction form
   1,139.60/1,572.48 = 667.46/x
3. Step 3: Cross multiply
   1,139.60x = 1,572.48 × 667.46
4. Step 4: Simplify right side
   1,139.60x = 1,049,571.43
5. Step 5: Solve for x
   x = 1,049,571.43/1,139.60
6. Step 6: Final answer
   x = 921.00