Finding the Fourth Proportional to 21,393.12, 29,530.32 and 12,895.55

Step by Step Solution

1. Step 1: Write the proportion equation
   21,393.12 : 29,530.32 = 12,895.55 : x
2. Step 2: Convert to fraction form
   21,393.12/29,530.32 = 12,895.55/x
3. Step 3: Cross multiply
   21,393.12x = 29,530.32 × 12,895.55
4. Step 4: Simplify right side
   21,393.12x = 380,809,570.42
5. Step 5: Solve for x
   x = 380,809,570.42/21,393.12
6. Step 6: Final answer
   x = 17,800.56