Finding the Fourth Proportional to 30,861.39, 42,595.91 and 21,911.70

Step by Step Solution

1. Step 1: Write the proportion equation
   30,861.39 : 42,595.91 = 21,911.70 : x
2. Step 2: Convert to fraction form
   30,861.39/42,595.91 = 21,911.70/x
3. Step 3: Cross multiply
   30,861.39x = 42,595.91 × 21,911.70
4. Step 4: Simplify right side
   30,861.39x = 933,348,801.15
5. Step 5: Solve for x
   x = 933,348,801.15/30,861.39
6. Step 6: Final answer
   x = 30,243.25