Finding the Fourth Proportional to 2,620.52, 3,930.89 and 865.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.52 : 3,930.89 = 865.67 : x
2. Step 2: Convert to fraction form
   2,620.52/3,930.89 = 865.67/x
3. Step 3: Cross multiply
   2,620.52x = 3,930.89 × 865.67
4. Step 4: Simplify right side
   2,620.52x = 3,402,829.56
5. Step 5: Solve for x
   x = 3,402,829.56/2,620.52
6. Step 6: Final answer
   x = 1,298.53