Finding the Fourth Proportional to 15,321.81, 21,144.18 and 8,607.72

Step by Step Solution

1. Step 1: Write the proportion equation
   15,321.81 : 21,144.18 = 8,607.72 : x
2. Step 2: Convert to fraction form
   15,321.81/21,144.18 = 8,607.72/x
3. Step 3: Cross multiply
   15,321.81x = 21,144.18 × 8,607.72
4. Step 4: Simplify right side
   15,321.81x = 182,003,181.07
5. Step 5: Solve for x
   x = 182,003,181.07/15,321.81
6. Step 6: Final answer
   x = 11,878.70