Finding the Fourth Proportional to 3,978.63, 5,486.09 and 2,719.89

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.63 : 5,486.09 = 2,719.89 : x
2. Step 2: Convert to fraction form
   3,978.63/5,486.09 = 2,719.89/x
3. Step 3: Cross multiply
   3,978.63x = 5,486.09 × 2,719.89
4. Step 4: Simplify right side
   3,978.63x = 14,921,547.73
5. Step 5: Solve for x
   x = 14,921,547.73/3,978.63
6. Step 6: Final answer
   x = 3,750.42