Finding the Fourth Proportional to 1,290.15, 1,935.98 and 771.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.15 : 1,935.98 = 771.42 : x
2. Step 2: Convert to fraction form
   1,290.15/1,935.98 = 771.42/x
3. Step 3: Cross multiply
   1,290.15x = 1,935.98 × 771.42
4. Step 4: Simplify right side
   1,290.15x = 1,493,449.83
5. Step 5: Solve for x
   x = 1,493,449.83/1,290.15
6. Step 6: Final answer
   x = 1,157.58