Finding the Fourth Proportional to 30,813.76, 42,538.72 and 21,365.92

Step by Step Solution

1. Step 1: Write the proportion equation
   30,813.76 : 42,538.72 = 21,365.92 : x
2. Step 2: Convert to fraction form
   30,813.76/42,538.72 = 21,365.92/x
3. Step 3: Cross multiply
   30,813.76x = 42,538.72 × 21,365.92
4. Step 4: Simplify right side
   30,813.76x = 908,878,888.42
5. Step 5: Solve for x
   x = 908,878,888.42/30,813.76
6. Step 6: Final answer
   x = 29,495.88