Finding the Fourth Proportional to 2,938.91, 4,406.61 and 990.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,938.91 : 4,406.61 = 990.86 : x
2. Step 2: Convert to fraction form
   2,938.91/4,406.61 = 990.86/x
3. Step 3: Cross multiply
   2,938.91x = 4,406.61 × 990.86
4. Step 4: Simplify right side
   2,938.91x = 4,366,333.58
5. Step 5: Solve for x
   x = 4,366,333.58/2,938.91
6. Step 6: Final answer
   x = 1,485.70