Finding the Fourth Proportional to 1,559.19, 2,150.81 and 990.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,559.19 : 2,150.81 = 990.98 : x
2. Step 2: Convert to fraction form
   1,559.19/2,150.81 = 990.98/x
3. Step 3: Cross multiply
   1,559.19x = 2,150.81 × 990.98
4. Step 4: Simplify right side
   1,559.19x = 2,131,409.69
5. Step 5: Solve for x
   x = 2,131,409.69/1,559.19
6. Step 6: Final answer
   x = 1,367.00