Finding the Fourth Proportional to 1,145.72, 1,719.12 and 496.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.72 : 1,719.12 = 496.64 : x
2. Step 2: Convert to fraction form
   1,145.72/1,719.12 = 496.64/x
3. Step 3: Cross multiply
   1,145.72x = 1,719.12 × 496.64
4. Step 4: Simplify right side
   1,145.72x = 853,783.76
5. Step 5: Solve for x
   x = 853,783.76/1,145.72
6. Step 6: Final answer
   x = 745.19