Finding the Fourth Proportional to 1,328.42, 1,992.72 and 1,039.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,328.42 : 1,992.72 = 1,039.34 : x
2. Step 2: Convert to fraction form
   1,328.42/1,992.72 = 1,039.34/x
3. Step 3: Cross multiply
   1,328.42x = 1,992.72 × 1,039.34
4. Step 4: Simplify right side
   1,328.42x = 2,071,113.60
5. Step 5: Solve for x
   x = 2,071,113.60/1,328.42
6. Step 6: Final answer
   x = 1,559.08