Finding the Third Proportional to 42,311 and 64,821

Step by Step Solution

1. Step 1: Write the proportion equation
   42,311 : 64,821 = 64,821 : x
2. Step 2: Convert to fraction form
   42,311/64,821 = 64,821/x
3. Step 3: Cross multiply
   42,311x = 64,821 × 64,821
4. Step 4: Simplify right side
   42,311x = 4,201,762,041
5. Step 5: Solve for x
   x = 4,201,762,041/42,311
6. Step 6: Final answer
   x = 99,306.61