Finding the Fourth Proportional to 2,124.72, 3,189.10 and 891.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,124.72 : 3,189.10 = 891.80 : x
2. Step 2: Convert to fraction form
   2,124.72/3,189.10 = 891.80/x
3. Step 3: Cross multiply
   2,124.72x = 3,189.10 × 891.80
4. Step 4: Simplify right side
   2,124.72x = 2,844,039.38
5. Step 5: Solve for x
   x = 2,844,039.38/2,124.72
6. Step 6: Final answer
   x = 1,338.55