Finding the Fourth Proportional to 13,420.58, 18,520.53 and 7,830.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,420.58 : 18,520.53 = 7,830.50 : x
2. Step 2: Convert to fraction form
   13,420.58/18,520.53 = 7,830.50/x
3. Step 3: Cross multiply
   13,420.58x = 18,520.53 × 7,830.50
4. Step 4: Simplify right side
   13,420.58x = 145,025,010.17
5. Step 5: Solve for x
   x = 145,025,010.17/13,420.58
6. Step 6: Final answer
   x = 10,806.17