Finding the Fourth Proportional to 1,139.82, 1,573.02 and 667.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.82 : 1,573.02 = 667.98 : x
2. Step 2: Convert to fraction form
   1,139.82/1,573.02 = 667.98/x
3. Step 3: Cross multiply
   1,139.82x = 1,573.02 × 667.98
4. Step 4: Simplify right side
   1,139.82x = 1,050,745.90
5. Step 5: Solve for x
   x = 1,050,745.90/1,139.82
6. Step 6: Final answer
   x = 921.85