Finding the Fourth Proportional to 7,086.83, 9,780.01 and 3,900.21

Step by Step Solution

1. Step 1: Write the proportion equation
   7,086.83 : 9,780.01 = 3,900.21 : x
2. Step 2: Convert to fraction form
   7,086.83/9,780.01 = 3,900.21/x
3. Step 3: Cross multiply
   7,086.83x = 9,780.01 × 3,900.21
4. Step 4: Simplify right side
   7,086.83x = 38,144,092.80
5. Step 5: Solve for x
   x = 38,144,092.80/7,086.83
6. Step 6: Final answer
   x = 5,382.39