Finding the Fourth Proportional to 42,988.38, 64,484.34 and 20,487.51

Step by Step Solution

1. Step 1: Write the proportion equation
   42,988.38 : 64,484.34 = 20,487.51 : x
2. Step 2: Convert to fraction form
   42,988.38/64,484.34 = 20,487.51/x
3. Step 3: Cross multiply
   42,988.38x = 64,484.34 × 20,487.51
4. Step 4: Simplify right side
   42,988.38x = 1,321,123,560.59
5. Step 5: Solve for x
   x = 1,321,123,560.59/42,988.38
6. Step 6: Final answer
   x = 30,732.11