Finding the Fourth Proportional to 1,245.89, 1,719.50 and 721.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,245.89 : 1,719.50 = 721.79 : x
2. Step 2: Convert to fraction form
   1,245.89/1,719.50 = 721.79/x
3. Step 3: Cross multiply
   1,245.89x = 1,719.50 × 721.79
4. Step 4: Simplify right side
   1,245.89x = 1,241,114.30
5. Step 5: Solve for x
   x = 1,241,114.30/1,245.89
6. Step 6: Final answer
   x = 996.17