Finding the Fourth Proportional to 1,139.72, 1,707.28 and 651.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.72 : 1,707.28 = 651.36 : x
2. Step 2: Convert to fraction form
   1,139.72/1,707.28 = 651.36/x
3. Step 3: Cross multiply
   1,139.72x = 1,707.28 × 651.36
4. Step 4: Simplify right side
   1,139.72x = 1,112,053.90
5. Step 5: Solve for x
   x = 1,112,053.90/1,139.72
6. Step 6: Final answer
   x = 975.73