Finding the Fourth Proportional to 42.88, 64.33 and 15.83

Step by Step Solution

1. Step 1: Write the proportion equation
   42.88 : 64.33 = 15.83 : x
2. Step 2: Convert to fraction form
   42.88/64.33 = 15.83/x
3. Step 3: Cross multiply
   42.88x = 64.33 × 15.83
4. Step 4: Simplify right side
   42.88x = 1,018.47
5. Step 5: Solve for x
   x = 1,018.47/42.88
6. Step 6: Final answer
   x = 23.75