Finding the Fourth Proportional to 20,315.88, 30,478.68 and 7,164.72

Step by Step Solution

1. Step 1: Write the proportion equation
   20,315.88 : 30,478.68 = 7,164.72 : x
2. Step 2: Convert to fraction form
   20,315.88/30,478.68 = 7,164.72/x
3. Step 3: Cross multiply
   20,315.88x = 30,478.68 × 7,164.72
4. Step 4: Simplify right side
   20,315.88x = 218,371,208.17
5. Step 5: Solve for x
   x = 218,371,208.17/20,315.88
6. Step 6: Final answer
   x = 10,748.79