Finding the Fourth Proportional to 42,719.59, 64,080.42 and 13,137.67

Step by Step Solution

1. Step 1: Write the proportion equation
   42,719.59 : 64,080.42 = 13,137.67 : x
2. Step 2: Convert to fraction form
   42,719.59/64,080.42 = 13,137.67/x
3. Step 3: Cross multiply
   42,719.59x = 64,080.42 × 13,137.67
4. Step 4: Simplify right side
   42,719.59x = 841,867,411.42
5. Step 5: Solve for x
   x = 841,867,411.42/42,719.59
6. Step 6: Final answer
   x = 19,706.82