Finding the Fourth Proportional to 1,377.81, 1,901.25 and 788.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.81 : 1,901.25 = 788.31 : x
2. Step 2: Convert to fraction form
   1,377.81/1,901.25 = 788.31/x
3. Step 3: Cross multiply
   1,377.81x = 1,901.25 × 788.31
4. Step 4: Simplify right side
   1,377.81x = 1,498,774.39
5. Step 5: Solve for x
   x = 1,498,774.39/1,377.81
6. Step 6: Final answer
   x = 1,087.79