Finding the Third Proportional to 11,520 and 21,136.50

Step by Step Solution

1. Step 1: Write the proportion equation
   11,520 : 21,136.50 = 21,136.50 : x
2. Step 2: Convert to fraction form
   11,520/21,136.50 = 21,136.50/x
3. Step 3: Cross multiply
   11,520x = 21,136.50 × 21,136.50
4. Step 4: Simplify right side
   11,520x = 446,751,632.25
5. Step 5: Solve for x
   x = 446,751,632.25/11,520
6. Step 6: Final answer
   x = 38,780.52