Finding the Fourth Proportional to 1,431.98, 1,975.68 and 842.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.98 : 1,975.68 = 842.72 : x
2. Step 2: Convert to fraction form
   1,431.98/1,975.68 = 842.72/x
3. Step 3: Cross multiply
   1,431.98x = 1,975.68 × 842.72
4. Step 4: Simplify right side
   1,431.98x = 1,664,945.05
5. Step 5: Solve for x
   x = 1,664,945.05/1,431.98
6. Step 6: Final answer
   x = 1,162.69