Finding the Fourth Proportional to 1,377.72, 1,901.20 and 788.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.72 : 1,901.20 = 788.24 : x
2. Step 2: Convert to fraction form
   1,377.72/1,901.20 = 788.24/x
3. Step 3: Cross multiply
   1,377.72x = 1,901.20 × 788.24
4. Step 4: Simplify right side
   1,377.72x = 1,498,601.89
5. Step 5: Solve for x
   x = 1,498,601.89/1,377.72
6. Step 6: Final answer
   x = 1,087.74