Finding the Fourth Proportional to 1,811.79, 2,498.72 and 1,290.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,811.79 : 2,498.72 = 1,290.15 : x
2. Step 2: Convert to fraction form
   1,811.79/2,498.72 = 1,290.15/x
3. Step 3: Cross multiply
   1,811.79x = 2,498.72 × 1,290.15
4. Step 4: Simplify right side
   1,811.79x = 3,223,717.16
5. Step 5: Solve for x
   x = 3,223,717.16/1,811.79
6. Step 6: Final answer
   x = 1,779.30