Finding the Third Proportional to 54,578.81 and 86,791.50

Step by Step Solution

1. Step 1: Write the proportion equation
   54,578.81 : 86,791.50 = 86,791.50 : x
2. Step 2: Convert to fraction form
   54,578.81/86,791.50 = 86,791.50/x
3. Step 3: Cross multiply
   54,578.81x = 86,791.50 × 86,791.50
4. Step 4: Simplify right side
   54,578.81x = 7,532,764,472.25
5. Step 5: Solve for x
   x = 7,532,764,472.25/54,578.81
6. Step 6: Final answer
   x = 138,016.28