Finding the Fourth Proportional to 78.57, 108.14 and 72.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78.57 : 108.14 = 72.50 : x
2. Step 2: Convert to fraction form
   78.57/108.14 = 72.50/x
3. Step 3: Cross multiply
   78.57x = 108.14 × 72.50
4. Step 4: Simplify right side
   78.57x = 7,839.25
5. Step 5: Solve for x
   x = 7,839.25/78.57
6. Step 6: Final answer
   x = 99.77