Finding the Fourth Proportional to 15,870.29, 21,899.81 and 8,699.06

Step by Step Solution

1. Step 1: Write the proportion equation
   15,870.29 : 21,899.81 = 8,699.06 : x
2. Step 2: Convert to fraction form
   15,870.29/21,899.81 = 8,699.06/x
3. Step 3: Cross multiply
   15,870.29x = 21,899.81 × 8,699.06
4. Step 4: Simplify right side
   15,870.29x = 190,507,608.18
5. Step 5: Solve for x
   x = 190,507,608.18/15,870.29
6. Step 6: Final answer
   x = 12,004.04