Finding the Fourth Proportional to 1,377.61, 1,900.97 and 780.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.61 : 1,900.97 = 780.13 : x
2. Step 2: Convert to fraction form
   1,377.61/1,900.97 = 780.13/x
3. Step 3: Cross multiply
   1,377.61x = 1,900.97 × 780.13
4. Step 4: Simplify right side
   1,377.61x = 1,483,003.73
5. Step 5: Solve for x
   x = 1,483,003.73/1,377.61
6. Step 6: Final answer
   x = 1,076.50