Finding the Fourth Proportional to 78.42, 108.18 and 52.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78.42 : 108.18 = 52.50 : x
2. Step 2: Convert to fraction form
   78.42/108.18 = 52.50/x
3. Step 3: Cross multiply
   78.42x = 108.18 × 52.50
4. Step 4: Simplify right side
   78.42x = 5,679.45
5. Step 5: Solve for x
   x = 5,679.45/78.42
6. Step 6: Final answer
   x = 72.42