Finding the Fourth Proportional to 2,538.78, 3,807.90 and 690.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,538.78 : 3,807.90 = 690.09 : x
2. Step 2: Convert to fraction form
   2,538.78/3,807.90 = 690.09/x
3. Step 3: Cross multiply
   2,538.78x = 3,807.90 × 690.09
4. Step 4: Simplify right side
   2,538.78x = 2,627,793.71
5. Step 5: Solve for x
   x = 2,627,793.71/2,538.78
6. Step 6: Final answer
   x = 1,035.06