Finding the Fourth Proportional to 2,638.55, 3,958.04 and 690.75

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.55 : 3,958.04 = 690.75 : x
2. Step 2: Convert to fraction form
   2,638.55/3,958.04 = 690.75/x
3. Step 3: Cross multiply
   2,638.55x = 3,958.04 × 690.75
4. Step 4: Simplify right side
   2,638.55x = 2,734,017.86
5. Step 5: Solve for x
   x = 2,734,017.86/2,638.55
6. Step 6: Final answer
   x = 1,036.18