Finding the Fourth Proportional to 20,927.34, 28,893.24 and 12,978

Step by Step Solution

1. Step 1: Write the proportion equation
   20,927.34 : 28,893.24 = 12,978 : x
2. Step 2: Convert to fraction form
   20,927.34/28,893.24 = 12,978/x
3. Step 3: Cross multiply
   20,927.34x = 28,893.24 × 12,978
4. Step 4: Simplify right side
   20,927.34x = 374,976,468.72
5. Step 5: Solve for x
   x = 374,976,468.72/20,927.34
6. Step 6: Final answer
   x = 17,918.02