Finding the Fourth Proportional to 2,139.31, 2,952.50 and 1,207.75

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.31 : 2,952.50 = 1,207.75 : x
2. Step 2: Convert to fraction form
   2,139.31/2,952.50 = 1,207.75/x
3. Step 3: Cross multiply
   2,139.31x = 2,952.50 × 1,207.75
4. Step 4: Simplify right side
   2,139.31x = 3,565,875.84
5. Step 5: Solve for x
   x = 3,565,875.84/2,139.31
6. Step 6: Final answer
   x = 1,666.83