Finding the Third Proportional to 31,578 and 72,915

Step by Step Solution

1. Step 1: Write the proportion equation
   31,578 : 72,915 = 72,915 : x
2. Step 2: Convert to fraction form
   31,578/72,915 = 72,915/x
3. Step 3: Cross multiply
   31,578x = 72,915 × 72,915
4. Step 4: Simplify right side
   31,578x = 5,316,597,225
5. Step 5: Solve for x
   x = 5,316,597,225/31,578
6. Step 6: Final answer
   x = 168,363.96