Finding the Fourth Proportional to 1,339.69, 2,010.15 and 690.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.69 : 2,010.15 = 690.07 : x
2. Step 2: Convert to fraction form
   1,339.69/2,010.15 = 690.07/x
3. Step 3: Cross multiply
   1,339.69x = 2,010.15 × 690.07
4. Step 4: Simplify right side
   1,339.69x = 1,387,144.21
5. Step 5: Solve for x
   x = 1,387,144.21/1,339.69
6. Step 6: Final answer
   x = 1,035.42