Finding the Fourth Proportional to 1,427.18, 2,139.69 and 907.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,427.18 : 2,139.69 = 907.70 : x
2. Step 2: Convert to fraction form
   1,427.18/2,139.69 = 907.70/x
3. Step 3: Cross multiply
   1,427.18x = 2,139.69 × 907.70
4. Step 4: Simplify right side
   1,427.18x = 1,942,196.61
5. Step 5: Solve for x
   x = 1,942,196.61/1,427.18
6. Step 6: Final answer
   x = 1,360.86