Finding the Fourth Proportional to 2,139.63, 3,210.98 and 907.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.63 : 3,210.98 = 907.38 : x
2. Step 2: Convert to fraction form
   2,139.63/3,210.98 = 907.38/x
3. Step 3: Cross multiply
   2,139.63x = 3,210.98 × 907.38
4. Step 4: Simplify right side
   2,139.63x = 2,913,574.50
5. Step 5: Solve for x
   x = 2,913,574.50/2,139.63
6. Step 6: Final answer
   x = 1,361.72