Finding the Fourth Proportional to 2,621.16, 3,931.72 and 889.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,621.16 : 3,931.72 = 889.80 : x
2. Step 2: Convert to fraction form
   2,621.16/3,931.72 = 889.80/x
3. Step 3: Cross multiply
   2,621.16x = 3,931.72 × 889.80
4. Step 4: Simplify right side
   2,621.16x = 3,498,444.46
5. Step 5: Solve for x
   x = 3,498,444.46/2,621.16
6. Step 6: Final answer
   x = 1,334.69