Finding the Fourth Proportional to 72.59, 108.90 and 31.50

Step by Step Solution

1. Step 1: Write the proportion equation
   72.59 : 108.90 = 31.50 : x
2. Step 2: Convert to fraction form
   72.59/108.90 = 31.50/x
3. Step 3: Cross multiply
   72.59x = 108.90 × 31.50
4. Step 4: Simplify right side
   72.59x = 3,429.81
5. Step 5: Solve for x
   x = 3,429.81/72.59
6. Step 6: Final answer
   x = 47.25