Finding the Fourth Proportional to 13,147.61, 18,141.32 and 7,770.95

Step by Step Solution

1. Step 1: Write the proportion equation
   13,147.61 : 18,141.32 = 7,770.95 : x
2. Step 2: Convert to fraction form
   13,147.61/18,141.32 = 7,770.95/x
3. Step 3: Cross multiply
   13,147.61x = 18,141.32 × 7,770.95
4. Step 4: Simplify right side
   13,147.61x = 140,975,309.30
5. Step 5: Solve for x
   x = 140,975,309.30/13,147.61
6. Step 6: Final answer
   x = 10,722.50