Finding the Fourth Proportional to 1,377.86, 1,901.35 and 780.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.86 : 1,901.35 = 780.18 : x
2. Step 2: Convert to fraction form
   1,377.86/1,901.35 = 780.18/x
3. Step 3: Cross multiply
   1,377.86x = 1,901.35 × 780.18
4. Step 4: Simplify right side
   1,377.86x = 1,483,400.00
5. Step 5: Solve for x
   x = 1,483,400.00/1,377.86
6. Step 6: Final answer
   x = 1,076.60