Finding the Fourth Proportional to 42,748.64, 64,443.32 and 39,894.56

Step by Step Solution

1. Step 1: Write the proportion equation
   42,748.64 : 64,443.32 = 39,894.56 : x
2. Step 2: Convert to fraction form
   42,748.64/64,443.32 = 39,894.56/x
3. Step 3: Cross multiply
   42,748.64x = 64,443.32 × 39,894.56
4. Step 4: Simplify right side
   42,748.64x = 2,570,937,896.34
5. Step 5: Solve for x
   x = 2,570,937,896.34/42,748.64
6. Step 6: Final answer
   x = 60,140.81