Finding the Fourth Proportional to 42,900.18, 64,372.29 and 20,436.30

Step by Step Solution

1. Step 1: Write the proportion equation
   42,900.18 : 64,372.29 = 20,436.30 : x
2. Step 2: Convert to fraction form
   42,900.18/64,372.29 = 20,436.30/x
3. Step 3: Cross multiply
   42,900.18x = 64,372.29 × 20,436.30
4. Step 4: Simplify right side
   42,900.18x = 1,315,531,430.13
5. Step 5: Solve for x
   x = 1,315,531,430.13/42,900.18
6. Step 6: Final answer
   x = 30,664.94