Finding the Fourth Proportional to 9,790.80, 13,499.88 and 7,139.36

Step by Step Solution

1. Step 1: Write the proportion equation
   9,790.80 : 13,499.88 = 7,139.36 : x
2. Step 2: Convert to fraction form
   9,790.80/13,499.88 = 7,139.36/x
3. Step 3: Cross multiply
   9,790.80x = 13,499.88 × 7,139.36
4. Step 4: Simplify right side
   9,790.80x = 96,380,503.28
5. Step 5: Solve for x
   x = 96,380,503.28/9,790.80
6. Step 6: Final answer
   x = 9,843.99