Finding the Fourth Proportional to 42,715.71, 64,032.42 and 28,679.58

Step by Step Solution

1. Step 1: Write the proportion equation
   42,715.71 : 64,032.42 = 28,679.58 : x
2. Step 2: Convert to fraction form
   42,715.71/64,032.42 = 28,679.58/x
3. Step 3: Cross multiply
   42,715.71x = 64,032.42 × 28,679.58
4. Step 4: Simplify right side
   42,715.71x = 1,836,422,911.98
5. Step 5: Solve for x
   x = 1,836,422,911.98/42,715.71
6. Step 6: Final answer
   x = 42,991.75