Finding the Fourth Proportional to 9,760.89, 13,470.21 and 5,780.55

Step by Step Solution

1. Step 1: Write the proportion equation
   9,760.89 : 13,470.21 = 5,780.55 : x
2. Step 2: Convert to fraction form
   9,760.89/13,470.21 = 5,780.55/x
3. Step 3: Cross multiply
   9,760.89x = 13,470.21 × 5,780.55
4. Step 4: Simplify right side
   9,760.89x = 77,865,222.42
5. Step 5: Solve for x
   x = 77,865,222.42/9,760.89
6. Step 6: Final answer
   x = 7,977.27