Finding the Fourth Proportional to 21,054.34, 31,564.86 and 7,905.25

Step by Step Solution

1. Step 1: Write the proportion equation
   21,054.34 : 31,564.86 = 7,905.25 : x
2. Step 2: Convert to fraction form
   21,054.34/31,564.86 = 7,905.25/x
3. Step 3: Cross multiply
   21,054.34x = 31,564.86 × 7,905.25
4. Step 4: Simplify right side
   21,054.34x = 249,528,109.52
5. Step 5: Solve for x
   x = 249,528,109.52/21,054.34
6. Step 6: Final answer
   x = 11,851.62