Finding the Fourth Proportional to 42,790.19, 64,166.56 and 20,307.31

Step by Step Solution

1. Step 1: Write the proportion equation
   42,790.19 : 64,166.56 = 20,307.31 : x
2. Step 2: Convert to fraction form
   42,790.19/64,166.56 = 20,307.31/x
3. Step 3: Cross multiply
   42,790.19x = 64,166.56 × 20,307.31
4. Step 4: Simplify right side
   42,790.19x = 1,303,050,305.76
5. Step 5: Solve for x
   x = 1,303,050,305.76/42,790.19
6. Step 6: Final answer
   x = 30,452.08