Finding the Fourth Proportional to 9,987.71, 13,783.71 and 5,740.15

Step by Step Solution

1. Step 1: Write the proportion equation
   9,987.71 : 13,783.71 = 5,740.15 : x
2. Step 2: Convert to fraction form
   9,987.71/13,783.71 = 5,740.15/x
3. Step 3: Cross multiply
   9,987.71x = 13,783.71 × 5,740.15
4. Step 4: Simplify right side
   9,987.71x = 79,120,562.96
5. Step 5: Solve for x
   x = 79,120,562.96/9,987.71
6. Step 6: Final answer
   x = 7,921.79