Finding the Fourth Proportional to 42,978.21, 64,470.33 and 17,993.04

Step by Step Solution

1. Step 1: Write the proportion equation
   42,978.21 : 64,470.33 = 17,993.04 : x
2. Step 2: Convert to fraction form
   42,978.21/64,470.33 = 17,993.04/x
3. Step 3: Cross multiply
   42,978.21x = 64,470.33 × 17,993.04
4. Step 4: Simplify right side
   42,978.21x = 1,160,017,226.50
5. Step 5: Solve for x
   x = 1,160,017,226.50/42,978.21
6. Step 6: Final answer
   x = 26,990.82