Finding the Fourth Proportional to 42,912.81, 64,053.57 and 39,904.47

Step by Step Solution

1. Step 1: Write the proportion equation
   42,912.81 : 64,053.57 = 39,904.47 : x
2. Step 2: Convert to fraction form
   42,912.81/64,053.57 = 39,904.47/x
3. Step 3: Cross multiply
   42,912.81x = 64,053.57 × 39,904.47
4. Step 4: Simplify right side
   42,912.81x = 2,556,023,762.46
5. Step 5: Solve for x
   x = 2,556,023,762.46/42,912.81
6. Step 6: Final answer
   x = 59,563.19