Finding the Fourth Proportional to 2,075.31, 3,112.16 and 905.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,075.31 : 3,112.16 = 905.67 : x
2. Step 2: Convert to fraction form
   2,075.31/3,112.16 = 905.67/x
3. Step 3: Cross multiply
   2,075.31x = 3,112.16 × 905.67
4. Step 4: Simplify right side
   2,075.31x = 2,818,585.42
5. Step 5: Solve for x
   x = 2,818,585.42/2,075.31
6. Step 6: Final answer
   x = 1,358.15