Finding the Fourth Proportional to 2,502.81, 3,753 and 858.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,502.81 : 3,753 = 858.78 : x
2. Step 2: Convert to fraction form
   2,502.81/3,753 = 858.78/x
3. Step 3: Cross multiply
   2,502.81x = 3,753 × 858.78
4. Step 4: Simplify right side
   2,502.81x = 3,223,001.34
5. Step 5: Solve for x
   x = 3,223,001.34/2,502.81
6. Step 6: Final answer
   x = 1,287.75