Finding the Fourth Proportional to 2,890.81, 4,335.43 and 810.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,890.81 : 4,335.43 = 810.69 : x
2. Step 2: Convert to fraction form
   2,890.81/4,335.43 = 810.69/x
3. Step 3: Cross multiply
   2,890.81x = 4,335.43 × 810.69
4. Step 4: Simplify right side
   2,890.81x = 3,514,672.98
5. Step 5: Solve for x
   x = 3,514,672.98/2,890.81
6. Step 6: Final answer
   x = 1,215.81