Finding the Fourth Proportional to 109.61, 164.21 and 82.59

Step by Step Solution

1. Step 1: Write the proportion equation
   109.61 : 164.21 = 82.59 : x
2. Step 2: Convert to fraction form
   109.61/164.21 = 82.59/x
3. Step 3: Cross multiply
   109.61x = 164.21 × 82.59
4. Step 4: Simplify right side
   109.61x = 13,561.69
5. Step 5: Solve for x
   x = 13,561.69/109.61
6. Step 6: Final answer
   x = 123.72