Finding the Fourth Proportional to 9,987.12, 13,782.21 and 5,510.87

Step by Step Solution

1. Step 1: Write the proportion equation
   9,987.12 : 13,782.21 = 5,510.87 : x
2. Step 2: Convert to fraction form
   9,987.12/13,782.21 = 5,510.87/x
3. Step 3: Cross multiply
   9,987.12x = 13,782.21 × 5,510.87
4. Step 4: Simplify right side
   9,987.12x = 75,951,967.62
5. Step 5: Solve for x
   x = 75,951,967.62/9,987.12
6. Step 6: Final answer
   x = 7,604.99