Finding the Fourth Proportional to 9,978.85, 13,770.39 and 5,726.98

Step by Step Solution

1. Step 1: Write the proportion equation
   9,978.85 : 13,770.39 = 5,726.98 : x
2. Step 2: Convert to fraction form
   9,978.85/13,770.39 = 5,726.98/x
3. Step 3: Cross multiply
   9,978.85x = 13,770.39 × 5,726.98
4. Step 4: Simplify right side
   9,978.85x = 78,862,748.12
5. Step 5: Solve for x
   x = 78,862,748.12/9,978.85
6. Step 6: Final answer
   x = 7,902.99