Finding the Fourth Proportional to 30,906.84, 42,644.28 and 20,853.93

Step by Step Solution

1. Step 1: Write the proportion equation
   30,906.84 : 42,644.28 = 20,853.93 : x
2. Step 2: Convert to fraction form
   30,906.84/42,644.28 = 20,853.93/x
3. Step 3: Cross multiply
   30,906.84x = 42,644.28 × 20,853.93
4. Step 4: Simplify right side
   30,906.84x = 889,300,830.02
5. Step 5: Solve for x
   x = 889,300,830.02/30,906.84
6. Step 6: Final answer
   x = 28,773.59