Finding the Third Proportional to 30,624 and 64,920

Step by Step Solution

1. Step 1: Write the proportion equation
   30,624 : 64,920 = 64,920 : x
2. Step 2: Convert to fraction form
   30,624/64,920 = 64,920/x
3. Step 3: Cross multiply
   30,624x = 64,920 × 64,920
4. Step 4: Simplify right side
   30,624x = 4,214,606,400
5. Step 5: Solve for x
   x = 4,214,606,400/30,624
6. Step 6: Final answer
   x = 137,624.29