Finding the Fourth Proportional to 21,019.76, 31,530.18 and 7,178.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,019.76 : 31,530.18 = 7,178.48 : x
2. Step 2: Convert to fraction form
   21,019.76/31,530.18 = 7,178.48/x
3. Step 3: Cross multiply
   21,019.76x = 31,530.18 × 7,178.48
4. Step 4: Simplify right side
   21,019.76x = 226,338,766.53
5. Step 5: Solve for x
   x = 226,338,766.53/21,019.76
6. Step 6: Final answer
   x = 10,767.90