Finding the Fourth Proportional to 12,978.78, 19,466.73 and 4,213.68

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.78 : 19,466.73 = 4,213.68 : x
2. Step 2: Convert to fraction form
   12,978.78/19,466.73 = 4,213.68/x
3. Step 3: Cross multiply
   12,978.78x = 19,466.73 × 4,213.68
4. Step 4: Simplify right side
   12,978.78x = 82,026,570.87
5. Step 5: Solve for x
   x = 82,026,570.87/12,978.78
6. Step 6: Final answer
   x = 6,320.05