Finding the Fourth Proportional to 21,780.72, 30,058.64 and 12,826.24

Step by Step Solution

1. Step 1: Write the proportion equation
   21,780.72 : 30,058.64 = 12,826.24 : x
2. Step 2: Convert to fraction form
   21,780.72/30,058.64 = 12,826.24/x
3. Step 3: Cross multiply
   21,780.72x = 30,058.64 × 12,826.24
4. Step 4: Simplify right side
   21,780.72x = 385,539,330.71
5. Step 5: Solve for x
   x = 385,539,330.71/21,780.72
6. Step 6: Final answer
   x = 17,700.95