Finding the Fourth Proportional to 2,087.78, 3,138.89 and 1,679.74

Step by Step Solution

1. Step 1: Write the proportion equation
   2,087.78 : 3,138.89 = 1,679.74 : x
2. Step 2: Convert to fraction form
   2,087.78/3,138.89 = 1,679.74/x
3. Step 3: Cross multiply
   2,087.78x = 3,138.89 × 1,679.74
4. Step 4: Simplify right side
   2,087.78x = 5,272,502.84
5. Step 5: Solve for x
   x = 5,272,502.84/2,087.78
6. Step 6: Final answer
   x = 2,525.42