Finding the Third Proportional to 17,709.75 and 21,415.50

Step by Step Solution

1. Step 1: Write the proportion equation
   17,709.75 : 21,415.50 = 21,415.50 : x
2. Step 2: Convert to fraction form
   17,709.75/21,415.50 = 21,415.50/x
3. Step 3: Cross multiply
   17,709.75x = 21,415.50 × 21,415.50
4. Step 4: Simplify right side
   17,709.75x = 458,623,640.25
5. Step 5: Solve for x
   x = 458,623,640.25/17,709.75
6. Step 6: Final answer
   x = 25,896.68