Finding the Fourth Proportional to 13,389.39, 18,477.31 and 7,421

Step by Step Solution

1. Step 1: Write the proportion equation
   13,389.39 : 18,477.31 = 7,421 : x
2. Step 2: Convert to fraction form
   13,389.39/18,477.31 = 7,421/x
3. Step 3: Cross multiply
   13,389.39x = 18,477.31 × 7,421
4. Step 4: Simplify right side
   13,389.39x = 137,120,117.51
5. Step 5: Solve for x
   x = 137,120,117.51/13,389.39
6. Step 6: Final answer
   x = 10,240.95