Finding the Fourth Proportional to 67.10, 100.20 and 58.10

Step by Step Solution

1. Step 1: Write the proportion equation
   67.10 : 100.20 = 58.10 : x
2. Step 2: Convert to fraction form
   67.10/100.20 = 58.10/x
3. Step 3: Cross multiply
   67.10x = 100.20 × 58.10
4. Step 4: Simplify right side
   67.10x = 5,821.33
5. Step 5: Solve for x
   x = 5,821.33/67.10
6. Step 6: Final answer
   x = 86.76