Finding the Fourth Proportional to 1,443.69, 1,990.98 and 971.19

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.69 : 1,990.98 = 971.19 : x
2. Step 2: Convert to fraction form
   1,443.69/1,990.98 = 971.19/x
3. Step 3: Cross multiply
   1,443.69x = 1,990.98 × 971.19
4. Step 4: Simplify right side
   1,443.69x = 1,933,619.87
5. Step 5: Solve for x
   x = 1,933,619.87/1,443.69
6. Step 6: Final answer
   x = 1,339.36