Finding the Fourth Proportional to 12,779.19, 17,638.43 and 7,477.47

Step by Step Solution

1. Step 1: Write the proportion equation
   12,779.19 : 17,638.43 = 7,477.47 : x
2. Step 2: Convert to fraction form
   12,779.19/17,638.43 = 7,477.47/x
3. Step 3: Cross multiply
   12,779.19x = 17,638.43 × 7,477.47
4. Step 4: Simplify right side
   12,779.19x = 131,890,793.78
5. Step 5: Solve for x
   x = 131,890,793.78/12,779.19
6. Step 6: Final answer
   x = 10,320.75