Finding the Fourth Proportional to 13,419.21, 18,518.15 and 7,450.72

Step by Step Solution

1. Step 1: Write the proportion equation
   13,419.21 : 18,518.15 = 7,450.72 : x
2. Step 2: Convert to fraction form
   13,419.21/18,518.15 = 7,450.72/x
3. Step 3: Cross multiply
   13,419.21x = 18,518.15 × 7,450.72
4. Step 4: Simplify right side
   13,419.21x = 137,973,564.40
5. Step 5: Solve for x
   x = 137,973,564.40/13,419.21
6. Step 6: Final answer
   x = 10,281.80