Finding the Fourth Proportional to 12,145.38, 18,219.78 and 5,121

Step by Step Solution

1. Step 1: Write the proportion equation
   12,145.38 : 18,219.78 = 5,121 : x
2. Step 2: Convert to fraction form
   12,145.38/18,219.78 = 5,121/x
3. Step 3: Cross multiply
   12,145.38x = 18,219.78 × 5,121
4. Step 4: Simplify right side
   12,145.38x = 93,303,493.38
5. Step 5: Solve for x
   x = 93,303,493.38/12,145.38
6. Step 6: Final answer
   x = 7,682.22