Finding the Fourth Proportional to 2,088.40, 3,128.34 and 989.43

Step by Step Solution

1. Step 1: Write the proportion equation
   2,088.40 : 3,128.34 = 989.43 : x
2. Step 2: Convert to fraction form
   2,088.40/3,128.34 = 989.43/x
3. Step 3: Cross multiply
   2,088.40x = 3,128.34 × 989.43
4. Step 4: Simplify right side
   2,088.40x = 3,095,257.80
5. Step 5: Solve for x
   x = 3,095,257.80/2,088.40
6. Step 6: Final answer
   x = 1,482.12