Finding the Fourth Proportional to 1,619.10, 2,234.52 and 989.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,619.10 : 2,234.52 = 989.91 : x
2. Step 2: Convert to fraction form
   1,619.10/2,234.52 = 989.91/x
3. Step 3: Cross multiply
   1,619.10x = 2,234.52 × 989.91
4. Step 4: Simplify right side
   1,619.10x = 2,211,973.69
5. Step 5: Solve for x
   x = 2,211,973.69/1,619.10
6. Step 6: Final answer
   x = 1,366.17