Finding the Fourth Proportional to 1,431.69, 2,146.67 and 690.85

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.69 : 2,146.67 = 690.85 : x
2. Step 2: Convert to fraction form
   1,431.69/2,146.67 = 690.85/x
3. Step 3: Cross multiply
   1,431.69x = 2,146.67 × 690.85
4. Step 4: Simplify right side
   1,431.69x = 1,483,023.33
5. Step 5: Solve for x
   x = 1,483,023.33/1,431.69
6. Step 6: Final answer
   x = 1,035.85