Finding the Fourth Proportional to 12,784.72, 17,638.40 and 7,477.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,784.72 : 17,638.40 = 7,477.60 : x
2. Step 2: Convert to fraction form
   12,784.72/17,638.40 = 7,477.60/x
3. Step 3: Cross multiply
   12,784.72x = 17,638.40 × 7,477.60
4. Step 4: Simplify right side
   12,784.72x = 131,892,899.84
5. Step 5: Solve for x
   x = 131,892,899.84/12,784.72
6. Step 6: Final answer
   x = 10,316.45