Finding the Fourth Proportional to 15,810.37, 21,818.72 and 8,640.59

Step by Step Solution

1. Step 1: Write the proportion equation
   15,810.37 : 21,818.72 = 8,640.59 : x
2. Step 2: Convert to fraction form
   15,810.37/21,818.72 = 8,640.59/x
3. Step 3: Cross multiply
   15,810.37x = 21,818.72 × 8,640.59
4. Step 4: Simplify right side
   15,810.37x = 188,526,526.35
5. Step 5: Solve for x
   x = 188,526,526.35/15,810.37
6. Step 6: Final answer
   x = 11,924.23