Finding the Fourth Proportional to 1,191.23, 1,643.34 and 771.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.23 : 1,643.34 = 771.72 : x
2. Step 2: Convert to fraction form
   1,191.23/1,643.34 = 771.72/x
3. Step 3: Cross multiply
   1,191.23x = 1,643.34 × 771.72
4. Step 4: Simplify right side
   1,191.23x = 1,268,196.17
5. Step 5: Solve for x
   x = 1,268,196.17/1,191.23
6. Step 6: Final answer
   x = 1,064.61