Finding the Fourth Proportional to 19,228.72, 28,869.63 and 13,290.98

Step by Step Solution

1. Step 1: Write the proportion equation
   19,228.72 : 28,869.63 = 13,290.98 : x
2. Step 2: Convert to fraction form
   19,228.72/28,869.63 = 13,290.98/x
3. Step 3: Cross multiply
   19,228.72x = 28,869.63 × 13,290.98
4. Step 4: Simplify right side
   19,228.72x = 383,705,530.59
5. Step 5: Solve for x
   x = 383,705,530.59/19,228.72
6. Step 6: Final answer
   x = 19,954.82