Finding the Fourth Proportional to 1,371.72, 2,042.56 and 1,336.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,371.72 : 2,042.56 = 1,336.88 : x
2. Step 2: Convert to fraction form
   1,371.72/2,042.56 = 1,336.88/x
3. Step 3: Cross multiply
   1,371.72x = 2,042.56 × 1,336.88
4. Step 4: Simplify right side
   1,371.72x = 2,730,657.61
5. Step 5: Solve for x
   x = 2,730,657.61/1,371.72
6. Step 6: Final answer
   x = 1,990.68