Finding the Fourth Proportional to 1,540.72, 2,126.34 and 842.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,540.72 : 2,126.34 = 842.20 : x
2. Step 2: Convert to fraction form
   1,540.72/2,126.34 = 842.20/x
3. Step 3: Cross multiply
   1,540.72x = 2,126.34 × 842.20
4. Step 4: Simplify right side
   1,540.72x = 1,790,803.55
5. Step 5: Solve for x
   x = 1,790,803.55/1,540.72
6. Step 6: Final answer
   x = 1,162.32