Finding the Fourth Proportional to 42,908.68, 64,373.94 and 13,330.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42,908.68 : 64,373.94 = 13,330.72 : x
2. Step 2: Convert to fraction form
   42,908.68/64,373.94 = 13,330.72/x
3. Step 3: Cross multiply
   42,908.68x = 64,373.94 × 13,330.72
4. Step 4: Simplify right side
   42,908.68x = 858,150,969.44
5. Step 5: Solve for x
   x = 858,150,969.44/42,908.68
6. Step 6: Final answer
   x = 19,999.47