Finding the Fourth Proportional to 2,139.69, 3,210.53 and 907.39

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.69 : 3,210.53 = 907.39 : x
2. Step 2: Convert to fraction form
   2,139.69/3,210.53 = 907.39/x
3. Step 3: Cross multiply
   2,139.69x = 3,210.53 × 907.39
4. Step 4: Simplify right side
   2,139.69x = 2,913,202.82
5. Step 5: Solve for x
   x = 2,913,202.82/2,139.69
6. Step 6: Final answer
   x = 1,361.51