Finding the Fourth Proportional to 2,457.79, 3,685.59 and 813.49

Step by Step Solution

1. Step 1: Write the proportion equation
   2,457.79 : 3,685.59 = 813.49 : x
2. Step 2: Convert to fraction form
   2,457.79/3,685.59 = 813.49/x
3. Step 3: Cross multiply
   2,457.79x = 3,685.59 × 813.49
4. Step 4: Simplify right side
   2,457.79x = 2,998,190.61
5. Step 5: Solve for x
   x = 2,998,190.61/2,457.79
6. Step 6: Final answer
   x = 1,219.87