Finding the Fourth Proportional to 2,123, 3,185.78 and 907

Step by Step Solution

1. Step 1: Write the proportion equation
   2,123 : 3,185.78 = 907 : x
2. Step 2: Convert to fraction form
   2,123/3,185.78 = 907/x
3. Step 3: Cross multiply
   2,123x = 3,185.78 × 907
4. Step 4: Simplify right side
   2,123x = 2,889,502.46
5. Step 5: Solve for x
   x = 2,889,502.46/2,123
6. Step 6: Final answer
   x = 1,361.05