Finding the Fourth Proportional to 13,090.50, 18,064.74 and 7,785.21

Step by Step Solution

1. Step 1: Write the proportion equation
   13,090.50 : 18,064.74 = 7,785.21 : x
2. Step 2: Convert to fraction form
   13,090.50/18,064.74 = 7,785.21/x
3. Step 3: Cross multiply
   13,090.50x = 18,064.74 × 7,785.21
4. Step 4: Simplify right side
   13,090.50x = 140,637,794.50
5. Step 5: Solve for x
   x = 140,637,794.50/13,090.50
6. Step 6: Final answer
   x = 10,743.50