Finding the Fourth Proportional to 1,378.74, 1,900.71 and 912.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.74 : 1,900.71 = 912.18 : x
2. Step 2: Convert to fraction form
   1,378.74/1,900.71 = 912.18/x
3. Step 3: Cross multiply
   1,378.74x = 1,900.71 × 912.18
4. Step 4: Simplify right side
   1,378.74x = 1,733,789.65
5. Step 5: Solve for x
   x = 1,733,789.65/1,378.74
6. Step 6: Final answer
   x = 1,257.52