Finding the Fourth Proportional to 31,048.46, 42,847.82 and 21,990.05

Step by Step Solution

1. Step 1: Write the proportion equation
   31,048.46 : 42,847.82 = 21,990.05 : x
2. Step 2: Convert to fraction form
   31,048.46/42,847.82 = 21,990.05/x
3. Step 3: Cross multiply
   31,048.46x = 42,847.82 × 21,990.05
4. Step 4: Simplify right side
   31,048.46x = 942,225,704.19
5. Step 5: Solve for x
   x = 942,225,704.19/31,048.46
6. Step 6: Final answer
   x = 30,346.94