Finding the Fourth Proportional to 42,912.69, 64,383.00 and 20,728.61

Step by Step Solution

1. Step 1: Write the proportion equation
   42,912.69 : 64,383.00 = 20,728.61 : x
2. Step 2: Convert to fraction form
   42,912.69/64,383.00 = 20,728.61/x
3. Step 3: Cross multiply
   42,912.69x = 64,383.00 × 20,728.61
4. Step 4: Simplify right side
   42,912.69x = 1,334,570,056.02
5. Step 5: Solve for x
   x = 1,334,570,056.02/42,912.69
6. Step 6: Final answer
   x = 31,099.66