Finding the Fourth Proportional to 3,920.40, 5,878.72 and 1,321.52

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.40 : 5,878.72 = 1,321.52 : x
2. Step 2: Convert to fraction form
   3,920.40/5,878.72 = 1,321.52/x
3. Step 3: Cross multiply
   3,920.40x = 5,878.72 × 1,321.52
4. Step 4: Simplify right side
   3,920.40x = 7,768,846.05
5. Step 5: Solve for x
   x = 7,768,846.05/3,920.40
6. Step 6: Final answer
   x = 1,981.65