Finding the Fourth Proportional to 13,172.79, 19,761.01 and 5,379.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,172.79 : 19,761.01 = 5,379.78 : x
2. Step 2: Convert to fraction form
   13,172.79/19,761.01 = 5,379.78/x
3. Step 3: Cross multiply
   13,172.79x = 19,761.01 × 5,379.78
4. Step 4: Simplify right side
   13,172.79x = 106,309,886.38
5. Step 5: Solve for x
   x = 106,309,886.38/13,172.79
6. Step 6: Final answer
   x = 8,070.42