Finding the Fourth Proportional to 12,821.90, 17,693.78 and 7,520.22

Step by Step Solution

1. Step 1: Write the proportion equation
   12,821.90 : 17,693.78 = 7,520.22 : x
2. Step 2: Convert to fraction form
   12,821.90/17,693.78 = 7,520.22/x
3. Step 3: Cross multiply
   12,821.90x = 17,693.78 × 7,520.22
4. Step 4: Simplify right side
   12,821.90x = 133,061,118.23
5. Step 5: Solve for x
   x = 133,061,118.23/12,821.90
6. Step 6: Final answer
   x = 10,377.64