Finding the Third Proportional to 5,478.75 and 8,215.88

Step by Step Solution

1. Step 1: Write the proportion equation
   5,478.75 : 8,215.88 = 8,215.88 : x
2. Step 2: Convert to fraction form
   5,478.75/8,215.88 = 8,215.88/x
3. Step 3: Cross multiply
   5,478.75x = 8,215.88 × 8,215.88
4. Step 4: Simplify right side
   5,478.75x = 67,500,602.02
5. Step 5: Solve for x
   x = 67,500,602.02/5,478.75
6. Step 6: Final answer
   x = 12,320.44