Finding the Fourth Proportional to 42,740.34, 64,111.33 and 13,158.15

Step by Step Solution

1. Step 1: Write the proportion equation
   42,740.34 : 64,111.33 = 13,158.15 : x
2. Step 2: Convert to fraction form
   42,740.34/64,111.33 = 13,158.15/x
3. Step 3: Cross multiply
   42,740.34x = 64,111.33 × 13,158.15
4. Step 4: Simplify right side
   42,740.34x = 843,586,272.87
5. Step 5: Solve for x
   x = 843,586,272.87/42,740.34
6. Step 6: Final answer
   x = 19,737.47