Finding the Fourth Proportional to 1,191.49, 1,643.71 and 771.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.49 : 1,643.71 = 771.98 : x
2. Step 2: Convert to fraction form
   1,191.49/1,643.71 = 771.98/x
3. Step 3: Cross multiply
   1,191.49x = 1,643.71 × 771.98
4. Step 4: Simplify right side
   1,191.49x = 1,268,902.54
5. Step 5: Solve for x
   x = 1,268,902.54/1,191.49
6. Step 6: Final answer
   x = 1,064.97