Finding the Fourth Proportional to 106.72, 159.72 and 74.50

Step by Step Solution

1. Step 1: Write the proportion equation
   106.72 : 159.72 = 74.50 : x
2. Step 2: Convert to fraction form
   106.72/159.72 = 74.50/x
3. Step 3: Cross multiply
   106.72x = 159.72 × 74.50
4. Step 4: Simplify right side
   106.72x = 11,899.14
5. Step 5: Solve for x
   x = 11,899.14/106.72
6. Step 6: Final answer
   x = 111.50