Finding the Fourth Proportional to 13,090.34, 18,064.72 and 7,121.96

Step by Step Solution

1. Step 1: Write the proportion equation
   13,090.34 : 18,064.72 = 7,121.96 : x
2. Step 2: Convert to fraction form
   13,090.34/18,064.72 = 7,121.96/x
3. Step 3: Cross multiply
   13,090.34x = 18,064.72 × 7,121.96
4. Step 4: Simplify right side
   13,090.34x = 128,656,199.57
5. Step 5: Solve for x
   x = 128,656,199.57/13,090.34
6. Step 6: Final answer
   x = 9,828.33