Finding the Fourth Proportional to 12,338.40, 18,507.42 and 2,978.34

Step by Step Solution

1. Step 1: Write the proportion equation
   12,338.40 : 18,507.42 = 2,978.34 : x
2. Step 2: Convert to fraction form
   12,338.40/18,507.42 = 2,978.34/x
3. Step 3: Cross multiply
   12,338.40x = 18,507.42 × 2,978.34
4. Step 4: Simplify right side
   12,338.40x = 55,121,389.28
5. Step 5: Solve for x
   x = 55,121,389.28/12,338.40
6. Step 6: Final answer
   x = 4,467.47