Finding the Fourth Proportional to 104.69, 156.69 and 86.46

Step by Step Solution

1. Step 1: Write the proportion equation
   104.69 : 156.69 = 86.46 : x
2. Step 2: Convert to fraction form
   104.69/156.69 = 86.46/x
3. Step 3: Cross multiply
   104.69x = 156.69 × 86.46
4. Step 4: Simplify right side
   104.69x = 13,547.42
5. Step 5: Solve for x
   x = 13,547.42/104.69
6. Step 6: Final answer
   x = 129.41