Finding the Fourth Proportional to 13,085.64, 18,057.33 and 7,780.86

Step by Step Solution

1. Step 1: Write the proportion equation
   13,085.64 : 18,057.33 = 7,780.86 : x
2. Step 2: Convert to fraction form
   13,085.64/18,057.33 = 7,780.86/x
3. Step 3: Cross multiply
   13,085.64x = 18,057.33 × 7,780.86
4. Step 4: Simplify right side
   13,085.64x = 140,501,556.70
5. Step 5: Solve for x
   x = 140,501,556.70/13,085.64
6. Step 6: Final answer
   x = 10,737.08