Finding the Fourth Proportional to 21,317.31, 31,976.37 and 7,280.55

Step by Step Solution

1. Step 1: Write the proportion equation
   21,317.31 : 31,976.37 = 7,280.55 : x
2. Step 2: Convert to fraction form
   21,317.31/31,976.37 = 7,280.55/x
3. Step 3: Cross multiply
   21,317.31x = 31,976.37 × 7,280.55
4. Step 4: Simplify right side
   21,317.31x = 232,805,524.20
5. Step 5: Solve for x
   x = 232,805,524.20/21,317.31
6. Step 6: Final answer
   x = 10,920.96