Finding the Fourth Proportional to 30,638.72, 42,280.34 and 18,722.00

Step by Step Solution

1. Step 1: Write the proportion equation
   30,638.72 : 42,280.34 = 18,722.00 : x
2. Step 2: Convert to fraction form
   30,638.72/42,280.34 = 18,722.00/x
3. Step 3: Cross multiply
   30,638.72x = 42,280.34 × 18,722.00
4. Step 4: Simplify right side
   30,638.72x = 791,572,220.47
5. Step 5: Solve for x
   x = 791,572,220.47/30,638.72
6. Step 6: Final answer
   x = 25,835.69