Finding the Fourth Proportional to 105.71, 158.55 and 59.91

Step by Step Solution

1. Step 1: Write the proportion equation
   105.71 : 158.55 = 59.91 : x
2. Step 2: Convert to fraction form
   105.71/158.55 = 59.91/x
3. Step 3: Cross multiply
   105.71x = 158.55 × 59.91
4. Step 4: Simplify right side
   105.71x = 9,498.73
5. Step 5: Solve for x
   x = 9,498.73/105.71
6. Step 6: Final answer
   x = 89.86