Finding the Third Proportional to 861.89 and 1,292.59

Step by Step Solution

1. Step 1: Write the proportion equation
   861.89 : 1,292.59 = 1,292.59 : x
2. Step 2: Convert to fraction form
   861.89/1,292.59 = 1,292.59/x
3. Step 3: Cross multiply
   861.89x = 1,292.59 × 1,292.59
4. Step 4: Simplify right side
   861.89x = 1,670,788.50
5. Step 5: Solve for x
   x = 1,670,788.50/861.89
6. Step 6: Final answer
   x = 1,938.52