Finding the Fourth Proportional to 21,147.15, 31,675.06 and 19,905

Step by Step Solution

1. Step 1: Write the proportion equation
   21,147.15 : 31,675.06 = 19,905 : x
2. Step 2: Convert to fraction form
   21,147.15/31,675.06 = 19,905/x
3. Step 3: Cross multiply
   21,147.15x = 31,675.06 × 19,905
4. Step 4: Simplify right side
   21,147.15x = 630,492,069.30
5. Step 5: Solve for x
   x = 630,492,069.30/21,147.15
6. Step 6: Final answer
   x = 29,814.52