Finding the Third Proportional to 8,940 and 21,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,940 : 21,139.50 = 21,139.50 : x
2. Step 2: Convert to fraction form
   8,940/21,139.50 = 21,139.50/x
3. Step 3: Cross multiply
   8,940x = 21,139.50 × 21,139.50
4. Step 4: Simplify right side
   8,940x = 446,878,460.25
5. Step 5: Solve for x
   x = 446,878,460.25/8,940
6. Step 6: Final answer
   x = 49,986.40