Finding the Fourth Proportional to 12,998.77, 19,499.38 and 3,638.79

Step by Step Solution

1. Step 1: Write the proportion equation
   12,998.77 : 19,499.38 = 3,638.79 : x
2. Step 2: Convert to fraction form
   12,998.77/19,499.38 = 3,638.79/x
3. Step 3: Cross multiply
   12,998.77x = 19,499.38 × 3,638.79
4. Step 4: Simplify right side
   12,998.77x = 70,954,139.85
5. Step 5: Solve for x
   x = 70,954,139.85/12,998.77
6. Step 6: Final answer
   x = 5,458.53