Finding the Fourth Proportional to 2,074.80, 3,111.96 and 613.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,074.80 : 3,111.96 = 613.92 : x
2. Step 2: Convert to fraction form
   2,074.80/3,111.96 = 613.92/x
3. Step 3: Cross multiply
   2,074.80x = 3,111.96 × 613.92
4. Step 4: Simplify right side
   2,074.80x = 1,910,494.48
5. Step 5: Solve for x
   x = 1,910,494.48/2,074.80
6. Step 6: Final answer
   x = 920.81