Finding the Fourth Proportional to 1,189.86, 1,783.59 and 779.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,189.86 : 1,783.59 = 779.82 : x
2. Step 2: Convert to fraction form
   1,189.86/1,783.59 = 779.82/x
3. Step 3: Cross multiply
   1,189.86x = 1,783.59 × 779.82
4. Step 4: Simplify right side
   1,189.86x = 1,390,879.15
5. Step 5: Solve for x
   x = 1,390,879.15/1,189.86
6. Step 6: Final answer
   x = 1,168.94