Finding the Fourth Proportional to 7,121.50, 9,827.73 and 3,978.34

Step by Step Solution

1. Step 1: Write the proportion equation
   7,121.50 : 9,827.73 = 3,978.34 : x
2. Step 2: Convert to fraction form
   7,121.50/9,827.73 = 3,978.34/x
3. Step 3: Cross multiply
   7,121.50x = 9,827.73 × 3,978.34
4. Step 4: Simplify right side
   7,121.50x = 39,098,051.37
5. Step 5: Solve for x
   x = 39,098,051.37/7,121.50
6. Step 6: Final answer
   x = 5,490.14