Finding the Fourth Proportional to 5,782.82, 7,984.15 and 3,897.21

Step by Step Solution

1. Step 1: Write the proportion equation
   5,782.82 : 7,984.15 = 3,897.21 : x
2. Step 2: Convert to fraction form
   5,782.82/7,984.15 = 3,897.21/x
3. Step 3: Cross multiply
   5,782.82x = 7,984.15 × 3,897.21
4. Step 4: Simplify right side
   5,782.82x = 31,115,849.81
5. Step 5: Solve for x
   x = 31,115,849.81/5,782.82
6. Step 6: Final answer
   x = 5,380.74