Finding the Fourth Proportional to 21,155.88, 31,736.52 and 7,109.88

Step by Step Solution

1. Step 1: Write the proportion equation
   21,155.88 : 31,736.52 = 7,109.88 : x
2. Step 2: Convert to fraction form
   21,155.88/31,736.52 = 7,109.88/x
3. Step 3: Cross multiply
   21,155.88x = 31,736.52 × 7,109.88
4. Step 4: Simplify right side
   21,155.88x = 225,642,848.82
5. Step 5: Solve for x
   x = 225,642,848.82/21,155.88
6. Step 6: Final answer
   x = 10,665.73