Finding the Fourth Proportional to 2,078.80, 2,811.50 and 2,078.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,078.80 : 2,811.50 = 2,078.80 : x
2. Step 2: Convert to fraction form
   2,078.80/2,811.50 = 2,078.80/x
3. Step 3: Cross multiply
   2,078.80x = 2,811.50 × 2,078.80
4. Step 4: Simplify right side
   2,078.80x = 5,844,546.20
5. Step 5: Solve for x
   x = 5,844,546.20/2,078.80
6. Step 6: Final answer
   x = 2,811.50