Finding the Fourth Proportional to 42,920.34, 64,389.78 and 17,619.90

Step by Step Solution

1. Step 1: Write the proportion equation
   42,920.34 : 64,389.78 = 17,619.90 : x
2. Step 2: Convert to fraction form
   42,920.34/64,389.78 = 17,619.90/x
3. Step 3: Cross multiply
   42,920.34x = 64,389.78 × 17,619.90
4. Step 4: Simplify right side
   42,920.34x = 1,134,541,484.62
5. Step 5: Solve for x
   x = 1,134,541,484.62/42,920.34
6. Step 6: Final answer
   x = 26,433.66