Finding the Fourth Proportional to 111.99, 167.35 and 91.72

Step by Step Solution

1. Step 1: Write the proportion equation
   111.99 : 167.35 = 91.72 : x
2. Step 2: Convert to fraction form
   111.99/167.35 = 91.72/x
3. Step 3: Cross multiply
   111.99x = 167.35 × 91.72
4. Step 4: Simplify right side
   111.99x = 15,349.34
5. Step 5: Solve for x
   x = 15,349.34/111.99
6. Step 6: Final answer
   x = 137.06