Finding the Third Proportional to 78,478.50 and 171,628.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,478.50 : 171,628.50 = 171,628.50 : x
2. Step 2: Convert to fraction form
   78,478.50/171,628.50 = 171,628.50/x
3. Step 3: Cross multiply
   78,478.50x = 171,628.50 × 171,628.50
4. Step 4: Simplify right side
   78,478.50x = 29,456,342,012.25
5. Step 5: Solve for x
   x = 29,456,342,012.25/78,478.50
6. Step 6: Final answer
   x = 375,342.83