Finding the Fourth Proportional to 2,176.72, 3,003.88 and 1,391.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,176.72 : 3,003.88 = 1,391.60 : x
2. Step 2: Convert to fraction form
   2,176.72/3,003.88 = 1,391.60/x
3. Step 3: Cross multiply
   2,176.72x = 3,003.88 × 1,391.60
4. Step 4: Simplify right side
   2,176.72x = 4,180,199.41
5. Step 5: Solve for x
   x = 4,180,199.41/2,176.72
6. Step 6: Final answer
   x = 1,920.41