Finding the Fourth Proportional to 13,091.36, 18,064.72 and 7,785.15

Step by Step Solution

1. Step 1: Write the proportion equation
   13,091.36 : 18,064.72 = 7,785.15 : x
2. Step 2: Convert to fraction form
   13,091.36/18,064.72 = 7,785.15/x
3. Step 3: Cross multiply
   13,091.36x = 18,064.72 × 7,785.15
4. Step 4: Simplify right side
   13,091.36x = 140,636,496.90
5. Step 5: Solve for x
   x = 140,636,496.90/13,091.36
6. Step 6: Final answer
   x = 10,742.70