Finding the Fourth Proportional to 9,987.56, 13,782.87 and 5,511.31

Step by Step Solution

1. Step 1: Write the proportion equation
   9,987.56 : 13,782.87 = 5,511.31 : x
2. Step 2: Convert to fraction form
   9,987.56/13,782.87 = 5,511.31/x
3. Step 3: Cross multiply
   9,987.56x = 13,782.87 × 5,511.31
4. Step 4: Simplify right side
   9,987.56x = 75,961,634.80
5. Step 5: Solve for x
   x = 75,961,634.80/9,987.56
6. Step 6: Final answer
   x = 7,605.63