Finding the Fourth Proportional to 12,291, 18,436.50 and 3,978

Step by Step Solution

1. Step 1: Write the proportion equation
   12,291 : 18,436.50 = 3,978 : x
2. Step 2: Convert to fraction form
   12,291/18,436.50 = 3,978/x
3. Step 3: Cross multiply
   12,291x = 18,436.50 × 3,978
4. Step 4: Simplify right side
   12,291x = 73,340,397
5. Step 5: Solve for x
   x = 73,340,397/12,291
6. Step 6: Final answer
   x = 5,967