Finding the Fourth Proportional to 105.84, 145.89 and 87.10

Step by Step Solution

1. Step 1: Write the proportion equation
   105.84 : 145.89 = 87.10 : x
2. Step 2: Convert to fraction form
   105.84/145.89 = 87.10/x
3. Step 3: Cross multiply
   105.84x = 145.89 × 87.10
4. Step 4: Simplify right side
   105.84x = 12,707.02
5. Step 5: Solve for x
   x = 12,707.02/105.84
6. Step 6: Final answer
   x = 120.06