Finding the Fourth Proportional to 2,120.13, 3,180.72 and 886.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,120.13 : 3,180.72 = 886.91 : x
2. Step 2: Convert to fraction form
   2,120.13/3,180.72 = 886.91/x
3. Step 3: Cross multiply
   2,120.13x = 3,180.72 × 886.91
4. Step 4: Simplify right side
   2,120.13x = 2,820,996.47
5. Step 5: Solve for x
   x = 2,820,996.47/2,120.13
6. Step 6: Final answer
   x = 1,330.58