Finding the Fourth Proportional to 9,980.39, 13,770.74 and 5,731.13

Step by Step Solution

1. Step 1: Write the proportion equation
   9,980.39 : 13,770.74 = 5,731.13 : x
2. Step 2: Convert to fraction form
   9,980.39/13,770.74 = 5,731.13/x
3. Step 3: Cross multiply
   9,980.39x = 13,770.74 × 5,731.13
4. Step 4: Simplify right side
   9,980.39x = 78,921,949.89
5. Step 5: Solve for x
   x = 78,921,949.89/9,980.39
6. Step 6: Final answer
   x = 7,907.70