Finding the Fourth Proportional to 38,638.72, 53,320.71 and 21,642.76

Step by Step Solution

1. Step 1: Write the proportion equation
   38,638.72 : 53,320.71 = 21,642.76 : x
2. Step 2: Convert to fraction form
   38,638.72/53,320.71 = 21,642.76/x
3. Step 3: Cross multiply
   38,638.72x = 53,320.71 × 21,642.76
4. Step 4: Simplify right side
   38,638.72x = 1,154,007,329.56
5. Step 5: Solve for x
   x = 1,154,007,329.56/38,638.72
6. Step 6: Final answer
   x = 29,866.60