Finding the Fourth Proportional to 59.99, 89.99 and 42.87

Step by Step Solution

1. Step 1: Write the proportion equation
   59.99 : 89.99 = 42.87 : x
2. Step 2: Convert to fraction form
   59.99/89.99 = 42.87/x
3. Step 3: Cross multiply
   59.99x = 89.99 × 42.87
4. Step 4: Simplify right side
   59.99x = 3,857.66
5. Step 5: Solve for x
   x = 3,857.66/59.99
6. Step 6: Final answer
   x = 64.31