Finding the Fourth Proportional to 15,742.76, 21,724.17 and 8,667.81

Step by Step Solution

1. Step 1: Write the proportion equation
   15,742.76 : 21,724.17 = 8,667.81 : x
2. Step 2: Convert to fraction form
   15,742.76/21,724.17 = 8,667.81/x
3. Step 3: Cross multiply
   15,742.76x = 21,724.17 × 8,667.81
4. Step 4: Simplify right side
   15,742.76x = 188,300,977.97
5. Step 5: Solve for x
   x = 188,300,977.97/15,742.76
6. Step 6: Final answer
   x = 11,961.12