Finding the Fourth Proportional to 15,870.92, 21,900.72 and 8,699.69

Step by Step Solution

1. Step 1: Write the proportion equation
   15,870.92 : 21,900.72 = 8,699.69 : x
2. Step 2: Convert to fraction form
   15,870.92/21,900.72 = 8,699.69/x
3. Step 3: Cross multiply
   15,870.92x = 21,900.72 × 8,699.69
4. Step 4: Simplify right side
   15,870.92x = 190,529,365.27
5. Step 5: Solve for x
   x = 190,529,365.27/15,870.92
6. Step 6: Final answer
   x = 12,004.94