Finding the Fourth Proportional to 72.42, 99.91 and 43.31

Step by Step Solution

1. Step 1: Write the proportion equation
   72.42 : 99.91 = 43.31 : x
2. Step 2: Convert to fraction form
   72.42/99.91 = 43.31/x
3. Step 3: Cross multiply
   72.42x = 99.91 × 43.31
4. Step 4: Simplify right side
   72.42x = 4,327.10
5. Step 5: Solve for x
   x = 4,327.10/72.42
6. Step 6: Final answer
   x = 59.75