Finding the Fourth Proportional to 1,238.33, 1,857.55 and 690.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,238.33 : 1,857.55 = 690.10 : x
2. Step 2: Convert to fraction form
   1,238.33/1,857.55 = 690.10/x
3. Step 3: Cross multiply
   1,238.33x = 1,857.55 × 690.10
4. Step 4: Simplify right side
   1,238.33x = 1,281,890.18
5. Step 5: Solve for x
   x = 1,281,890.18/1,238.33
6. Step 6: Final answer
   x = 1,035.18