Finding the Fourth Proportional to 109.16, 162.84 and 105.78

Step by Step Solution

1. Step 1: Write the proportion equation
   109.16 : 162.84 = 105.78 : x
2. Step 2: Convert to fraction form
   109.16/162.84 = 105.78/x
3. Step 3: Cross multiply
   109.16x = 162.84 × 105.78
4. Step 4: Simplify right side
   109.16x = 17,225.22
5. Step 5: Solve for x
   x = 17,225.22/109.16
6. Step 6: Final answer
   x = 157.80