Finding the Fourth Proportional to 42,711.40, 64,073.23 and 13,131.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42,711.40 : 64,073.23 = 13,131.72 : x
2. Step 2: Convert to fraction form
   42,711.40/64,073.23 = 13,131.72/x
3. Step 3: Cross multiply
   42,711.40x = 64,073.23 × 13,131.72
4. Step 4: Simplify right side
   42,711.40x = 841,391,683.03
5. Step 5: Solve for x
   x = 841,391,683.03/42,711.40
6. Step 6: Final answer
   x = 19,699.46