Finding the Fourth Proportional to 13,608.96, 18,779.76 and 7,640.52

Step by Step Solution

1. Step 1: Write the proportion equation
   13,608.96 : 18,779.76 = 7,640.52 : x
2. Step 2: Convert to fraction form
   13,608.96/18,779.76 = 7,640.52/x
3. Step 3: Cross multiply
   13,608.96x = 18,779.76 × 7,640.52
4. Step 4: Simplify right side
   13,608.96x = 143,487,131.88
5. Step 5: Solve for x
   x = 143,487,131.88/13,608.96
6. Step 6: Final answer
   x = 10,543.58