Finding the Fourth Proportional to 1,139.94, 1,573.51 and 667.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.94 : 1,573.51 = 667.99 : x
2. Step 2: Convert to fraction form
   1,139.94/1,573.51 = 667.99/x
3. Step 3: Cross multiply
   1,139.94x = 1,573.51 × 667.99
4. Step 4: Simplify right side
   1,139.94x = 1,051,090.61
5. Step 5: Solve for x
   x = 1,051,090.61/1,139.94
6. Step 6: Final answer
   x = 922.06