Finding the Fourth Proportional to 2,620.32, 3,931.10 and 771.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.32 : 3,931.10 = 771.50 : x
2. Step 2: Convert to fraction form
   2,620.32/3,931.10 = 771.50/x
3. Step 3: Cross multiply
   2,620.32x = 3,931.10 × 771.50
4. Step 4: Simplify right side
   2,620.32x = 3,032,843.65
5. Step 5: Solve for x
   x = 3,032,843.65/2,620.32
6. Step 6: Final answer
   x = 1,157.43