Finding the Fourth Proportional to 1,378.08, 1,901.61 and 780.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.08 : 1,901.61 = 780.53 : x
2. Step 2: Convert to fraction form
   1,378.08/1,901.61 = 780.53/x
3. Step 3: Cross multiply
   1,378.08x = 1,901.61 × 780.53
4. Step 4: Simplify right side
   1,378.08x = 1,484,254.15
5. Step 5: Solve for x
   x = 1,484,254.15/1,378.08
6. Step 6: Final answer
   x = 1,077.04