Finding the Third Proportional to 21,111 and 28,420.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,111 : 28,420.50 = 28,420.50 : x
2. Step 2: Convert to fraction form
   21,111/28,420.50 = 28,420.50/x
3. Step 3: Cross multiply
   21,111x = 28,420.50 × 28,420.50
4. Step 4: Simplify right side
   21,111x = 807,724,820.25
5. Step 5: Solve for x
   x = 807,724,820.25/21,111
6. Step 6: Final answer
   x = 38,260.85