Finding the Fourth Proportional to 31,012.10, 42,808.85 and 21,984.64

Step by Step Solution

1. Step 1: Write the proportion equation
   31,012.10 : 42,808.85 = 21,984.64 : x
2. Step 2: Convert to fraction form
   31,012.10/42,808.85 = 21,984.64/x
3. Step 3: Cross multiply
   31,012.10x = 42,808.85 × 21,984.64
4. Step 4: Simplify right side
   31,012.10x = 941,137,104.00
5. Step 5: Solve for x
   x = 941,137,104.00/31,012.10
6. Step 6: Final answer
   x = 30,347.42