Finding the Fourth Proportional to 13,689.76, 18,890.52 and 7,722.34

Step by Step Solution

1. Step 1: Write the proportion equation
   13,689.76 : 18,890.52 = 7,722.34 : x
2. Step 2: Convert to fraction form
   13,689.76/18,890.52 = 7,722.34/x
3. Step 3: Cross multiply
   13,689.76x = 18,890.52 × 7,722.34
4. Step 4: Simplify right side
   13,689.76x = 145,879,018.22
5. Step 5: Solve for x
   x = 145,879,018.22/13,689.76
6. Step 6: Final answer
   x = 10,656.07