Finding the Fourth Proportional to 2,458.84, 3,390.78 and 2,085.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,458.84 : 3,390.78 = 2,085.40 : x
2. Step 2: Convert to fraction form
   2,458.84/3,390.78 = 2,085.40/x
3. Step 3: Cross multiply
   2,458.84x = 3,390.78 × 2,085.40
4. Step 4: Simplify right side
   2,458.84x = 7,071,132.61
5. Step 5: Solve for x
   x = 7,071,132.61/2,458.84
6. Step 6: Final answer
   x = 2,875.80