Finding the Fourth Proportional to 11,586.72, 15,987 and 7,816.88

Step by Step Solution

1. Step 1: Write the proportion equation
   11,586.72 : 15,987 = 7,816.88 : x
2. Step 2: Convert to fraction form
   11,586.72/15,987 = 7,816.88/x
3. Step 3: Cross multiply
   11,586.72x = 15,987 × 7,816.88
4. Step 4: Simplify right side
   11,586.72x = 124,968,460.56
5. Step 5: Solve for x
   x = 124,968,460.56/11,586.72
6. Step 6: Final answer
   x = 10,785.49