Finding the Fourth Proportional to 1,378.06, 1,901.80 and 788.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,378.06 : 1,901.80 = 788.78 : x
2. Step 2: Convert to fraction form
   1,378.06/1,901.80 = 788.78/x
3. Step 3: Cross multiply
   1,378.06x = 1,901.80 × 788.78
4. Step 4: Simplify right side
   1,378.06x = 1,500,101.80
5. Step 5: Solve for x
   x = 1,500,101.80/1,378.06
6. Step 6: Final answer
   x = 1,088.56