Finding the Fourth Proportional to 8,978, 12,390.72 and 5,252

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978 : 12,390.72 = 5,252 : x
2. Step 2: Convert to fraction form
   8,978/12,390.72 = 5,252/x
3. Step 3: Cross multiply
   8,978x = 12,390.72 × 5,252
4. Step 4: Simplify right side
   8,978x = 65,076,061.44
5. Step 5: Solve for x
   x = 65,076,061.44/8,978
6. Step 6: Final answer
   x = 7,248.39