Finding the Fourth Proportional to 42.89, 64.34 and 15.84

Step by Step Solution

1. Step 1: Write the proportion equation
   42.89 : 64.34 = 15.84 : x
2. Step 2: Convert to fraction form
   42.89/64.34 = 15.84/x
3. Step 3: Cross multiply
   42.89x = 64.34 × 15.84
4. Step 4: Simplify right side
   42.89x = 1,018.74
5. Step 5: Solve for x
   x = 1,018.74/42.89
6. Step 6: Final answer
   x = 23.75