Finding the Fourth Proportional to 109.32, 150.80 and 71.91

Step by Step Solution

1. Step 1: Write the proportion equation
   109.32 : 150.80 = 71.91 : x
2. Step 2: Convert to fraction form
   109.32/150.80 = 71.91/x
3. Step 3: Cross multiply
   109.32x = 150.80 × 71.91
4. Step 4: Simplify right side
   109.32x = 10,844.03
5. Step 5: Solve for x
   x = 10,844.03/109.32
6. Step 6: Final answer
   x = 99.20