Finding the Fourth Proportional to 42,710.40, 64,386 and 39,856

Step by Step Solution

1. Step 1: Write the proportion equation
   42,710.40 : 64,386 = 39,856 : x
2. Step 2: Convert to fraction form
   42,710.40/64,386 = 39,856/x
3. Step 3: Cross multiply
   42,710.40x = 64,386 × 39,856
4. Step 4: Simplify right side
   42,710.40x = 2,566,168,416
5. Step 5: Solve for x
   x = 2,566,168,416/42,710.40
6. Step 6: Final answer
   x = 60,082.99