Finding the Third Proportional to 1,258.50 and 2,689.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,258.50 : 2,689.50 = 2,689.50 : x
2. Step 2: Convert to fraction form
   1,258.50/2,689.50 = 2,689.50/x
3. Step 3: Cross multiply
   1,258.50x = 2,689.50 × 2,689.50
4. Step 4: Simplify right side
   1,258.50x = 7,233,410.25
5. Step 5: Solve for x
   x = 7,233,410.25/1,258.50
6. Step 6: Final answer
   x = 5,747.64