Finding the Fourth Proportional to 3,290.87, 4,939.45 and 1,212.89

Step by Step Solution

1. Step 1: Write the proportion equation
   3,290.87 : 4,939.45 = 1,212.89 : x
2. Step 2: Convert to fraction form
   3,290.87/4,939.45 = 1,212.89/x
3. Step 3: Cross multiply
   3,290.87x = 4,939.45 × 1,212.89
4. Step 4: Simplify right side
   3,290.87x = 5,990,981.78
5. Step 5: Solve for x
   x = 5,990,981.78/3,290.87
6. Step 6: Final answer
   x = 1,820.48