Finding the Fourth Proportional to 109.78, 164.72 and 103.97

Step by Step Solution

1. Step 1: Write the proportion equation
   109.78 : 164.72 = 103.97 : x
2. Step 2: Convert to fraction form
   109.78/164.72 = 103.97/x
3. Step 3: Cross multiply
   109.78x = 164.72 × 103.97
4. Step 4: Simplify right side
   109.78x = 17,125.94
5. Step 5: Solve for x
   x = 17,125.94/109.78
6. Step 6: Final answer
   x = 156.00