Finding the Fourth Proportional to 9,987.56, 13,782.81 and 5,511.28

Step by Step Solution

1. Step 1: Write the proportion equation
   9,987.56 : 13,782.81 = 5,511.28 : x
2. Step 2: Convert to fraction form
   9,987.56/13,782.81 = 5,511.28/x
3. Step 3: Cross multiply
   9,987.56x = 13,782.81 × 5,511.28
4. Step 4: Simplify right side
   9,987.56x = 75,960,867.38
5. Step 5: Solve for x
   x = 75,960,867.38/9,987.56
6. Step 6: Final answer
   x = 7,605.54