Finding the Fourth Proportional to 13,388.57, 18,476.01 and 7,420.22

Step by Step Solution

1. Step 1: Write the proportion equation
   13,388.57 : 18,476.01 = 7,420.22 : x
2. Step 2: Convert to fraction form
   13,388.57/18,476.01 = 7,420.22/x
3. Step 3: Cross multiply
   13,388.57x = 18,476.01 × 7,420.22
4. Step 4: Simplify right side
   13,388.57x = 137,096,058.92
5. Step 5: Solve for x
   x = 137,096,058.92/13,388.57
6. Step 6: Final answer
   x = 10,239.78