Finding the Fourth Proportional to 2,619.93, 3,931.86 and 1,387.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.93 : 3,931.86 = 1,387.61 : x
2. Step 2: Convert to fraction form
   2,619.93/3,931.86 = 1,387.61/x
3. Step 3: Cross multiply
   2,619.93x = 3,931.86 × 1,387.61
4. Step 4: Simplify right side
   2,619.93x = 5,455,910.66
5. Step 5: Solve for x
   x = 5,455,910.66/2,619.93
6. Step 6: Final answer
   x = 2,082.47