Finding the Fourth Proportional to 2,069.90, 3,105 and 771.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,069.90 : 3,105 = 771.38 : x
2. Step 2: Convert to fraction form
   2,069.90/3,105 = 771.38/x
3. Step 3: Cross multiply
   2,069.90x = 3,105 × 771.38
4. Step 4: Simplify right side
   2,069.90x = 2,395,119.38
5. Step 5: Solve for x
   x = 2,395,119.38/2,069.90
6. Step 6: Final answer
   x = 1,157.12