Finding the Fourth Proportional to 42,668.12, 64,003.12 and 13,085.30

Step by Step Solution

1. Step 1: Write the proportion equation
   42,668.12 : 64,003.12 = 13,085.30 : x
2. Step 2: Convert to fraction form
   42,668.12/64,003.12 = 13,085.30/x
3. Step 3: Cross multiply
   42,668.12x = 64,003.12 × 13,085.30
4. Step 4: Simplify right side
   42,668.12x = 837,500,026.14
5. Step 5: Solve for x
   x = 837,500,026.14/42,668.12
6. Step 6: Final answer
   x = 19,628.24