Finding the Fourth Proportional to 2,120.86, 3,180.89 and 887.94

Step by Step Solution

1. Step 1: Write the proportion equation
   2,120.86 : 3,180.89 = 887.94 : x
2. Step 2: Convert to fraction form
   2,120.86/3,180.89 = 887.94/x
3. Step 3: Cross multiply
   2,120.86x = 3,180.89 × 887.94
4. Step 4: Simplify right side
   2,120.86x = 2,824,419.12
5. Step 5: Solve for x
   x = 2,824,419.12/2,120.86
6. Step 6: Final answer
   x = 1,331.74