Finding the Fourth Proportional to 12,686.90, 19,030.89 and 3,921.98

Step by Step Solution

1. Step 1: Write the proportion equation
   12,686.90 : 19,030.89 = 3,921.98 : x
2. Step 2: Convert to fraction form
   12,686.90/19,030.89 = 3,921.98/x
3. Step 3: Cross multiply
   12,686.90x = 19,030.89 × 3,921.98
4. Step 4: Simplify right side
   12,686.90x = 74,638,769.96
5. Step 5: Solve for x
   x = 74,638,769.96/12,686.90
6. Step 6: Final answer
   x = 5,883.14