Finding the Fourth Proportional to 1,431.43, 1,975.76 and 842.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.43 : 1,975.76 = 842.15 : x
2. Step 2: Convert to fraction form
   1,431.43/1,975.76 = 842.15/x
3. Step 3: Cross multiply
   1,431.43x = 1,975.76 × 842.15
4. Step 4: Simplify right side
   1,431.43x = 1,663,890.17
5. Step 5: Solve for x
   x = 1,663,890.17/1,431.43
6. Step 6: Final answer
   x = 1,162.40