Finding the Fourth Proportional to 21,988.12, 32,978.52 and 7,945.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,988.12 : 32,978.52 = 7,945.42 : x
2. Step 2: Convert to fraction form
   21,988.12/32,978.52 = 7,945.42/x
3. Step 3: Cross multiply
   21,988.12x = 32,978.52 × 7,945.42
4. Step 4: Simplify right side
   21,988.12x = 262,028,192.38
5. Step 5: Solve for x
   x = 262,028,192.38/21,988.12
6. Step 6: Final answer
   x = 11,916.81