Finding the Fourth Proportional to 2,767.81, 4,151.21 and 918.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,767.81 : 4,151.21 = 918.72 : x
2. Step 2: Convert to fraction form
   2,767.81/4,151.21 = 918.72/x
3. Step 3: Cross multiply
   2,767.81x = 4,151.21 × 918.72
4. Step 4: Simplify right side
   2,767.81x = 3,813,799.65
5. Step 5: Solve for x
   x = 3,813,799.65/2,767.81
6. Step 6: Final answer
   x = 1,377.91