Finding the Third Proportional to 1,139.50 and 1,691

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.50 : 1,691 = 1,691 : x
2. Step 2: Convert to fraction form
   1,139.50/1,691 = 1,691/x
3. Step 3: Cross multiply
   1,139.50x = 1,691 × 1,691
4. Step 4: Simplify right side
   1,139.50x = 2,859,481
5. Step 5: Solve for x
   x = 2,859,481/1,139.50
6. Step 6: Final answer
   x = 2,509.42