Finding the Fourth Proportional to 8,221.38, 12,321.69 and 5,258.70

Step by Step Solution

1. Step 1: Write the proportion equation
   8,221.38 : 12,321.69 = 5,258.70 : x
2. Step 2: Convert to fraction form
   8,221.38/12,321.69 = 5,258.70/x
3. Step 3: Cross multiply
   8,221.38x = 12,321.69 × 5,258.70
4. Step 4: Simplify right side
   8,221.38x = 64,796,071.20
5. Step 5: Solve for x
   x = 64,796,071.20/8,221.38
6. Step 6: Final answer
   x = 7,881.41