Finding the Fourth Proportional to 13,139.98, 19,705.74 and 4,372.54

Step by Step Solution

1. Step 1: Write the proportion equation
   13,139.98 : 19,705.74 = 4,372.54 : x
2. Step 2: Convert to fraction form
   13,139.98/19,705.74 = 4,372.54/x
3. Step 3: Cross multiply
   13,139.98x = 19,705.74 × 4,372.54
4. Step 4: Simplify right side
   13,139.98x = 86,164,136.38
5. Step 5: Solve for x
   x = 86,164,136.38/13,139.98
6. Step 6: Final answer
   x = 6,557.40