Finding the Fourth Proportional to 42,665.90, 64,006.42 and 14,579.40

Step by Step Solution

1. Step 1: Write the proportion equation
   42,665.90 : 64,006.42 = 14,579.40 : x
2. Step 2: Convert to fraction form
   42,665.90/64,006.42 = 14,579.40/x
3. Step 3: Cross multiply
   42,665.90x = 64,006.42 × 14,579.40
4. Step 4: Simplify right side
   42,665.90x = 933,175,199.75
5. Step 5: Solve for x
   x = 933,175,199.75/42,665.90
6. Step 6: Final answer
   x = 21,871.69