Finding the Fourth Proportional to 1,335.86, 1,843.60 and 776.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,335.86 : 1,843.60 = 776.50 : x
2. Step 2: Convert to fraction form
   1,335.86/1,843.60 = 776.50/x
3. Step 3: Cross multiply
   1,335.86x = 1,843.60 × 776.50
4. Step 4: Simplify right side
   1,335.86x = 1,431,555.40
5. Step 5: Solve for x
   x = 1,431,555.40/1,335.86
6. Step 6: Final answer
   x = 1,071.64