Finding the Fourth Proportional to 1,431.34, 1,975.61 and 842.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.34 : 1,975.61 = 842.28 : x
2. Step 2: Convert to fraction form
   1,431.34/1,975.61 = 842.28/x
3. Step 3: Cross multiply
   1,431.34x = 1,975.61 × 842.28
4. Step 4: Simplify right side
   1,431.34x = 1,664,016.79
5. Step 5: Solve for x
   x = 1,664,016.79/1,431.34
6. Step 6: Final answer
   x = 1,162.56