Finding the Fourth Proportional to 2,638.30, 3,956.91 and 907.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.30 : 3,956.91 = 907.06 : x
2. Step 2: Convert to fraction form
   2,638.30/3,956.91 = 907.06/x
3. Step 3: Cross multiply
   2,638.30x = 3,956.91 × 907.06
4. Step 4: Simplify right side
   2,638.30x = 3,589,154.78
5. Step 5: Solve for x
   x = 3,589,154.78/2,638.30
6. Step 6: Final answer
   x = 1,360.40