Finding the Fourth Proportional to 42,689.48, 64,043.74 and 13,110.30

Step by Step Solution

1. Step 1: Write the proportion equation
   42,689.48 : 64,043.74 = 13,110.30 : x
2. Step 2: Convert to fraction form
   42,689.48/64,043.74 = 13,110.30/x
3. Step 3: Cross multiply
   42,689.48x = 64,043.74 × 13,110.30
4. Step 4: Simplify right side
   42,689.48x = 839,632,644.52
5. Step 5: Solve for x
   x = 839,632,644.52/42,689.48
6. Step 6: Final answer
   x = 19,668.37