Finding the Fourth Proportional to 42,606, 63,919.40 and 13,422

Step by Step Solution

1. Step 1: Write the proportion equation
   42,606 : 63,919.40 = 13,422 : x
2. Step 2: Convert to fraction form
   42,606/63,919.40 = 13,422/x
3. Step 3: Cross multiply
   42,606x = 63,919.40 × 13,422
4. Step 4: Simplify right side
   42,606x = 857,926,186.80
5. Step 5: Solve for x
   x = 857,926,186.80/42,606
6. Step 6: Final answer
   x = 20,136.28