Finding the Fourth Proportional to 76.57, 105.71 and 72.01

Step by Step Solution

1. Step 1: Write the proportion equation
   76.57 : 105.71 = 72.01 : x
2. Step 2: Convert to fraction form
   76.57/105.71 = 72.01/x
3. Step 3: Cross multiply
   76.57x = 105.71 × 72.01
4. Step 4: Simplify right side
   76.57x = 7,612.25
5. Step 5: Solve for x
   x = 7,612.25/76.57
6. Step 6: Final answer
   x = 99.42