Finding the Third Proportional to 81,931.50 and 178,686

Step by Step Solution

1. Step 1: Write the proportion equation
   81,931.50 : 178,686 = 178,686 : x
2. Step 2: Convert to fraction form
   81,931.50/178,686 = 178,686/x
3. Step 3: Cross multiply
   81,931.50x = 178,686 × 178,686
4. Step 4: Simplify right side
   81,931.50x = 31,928,686,596
5. Step 5: Solve for x
   x = 31,928,686,596/81,931.50
6. Step 6: Final answer
   x = 389,699.77