Finding the Fourth Proportional to 78.42, 108.18 and 53.88

Step by Step Solution

1. Step 1: Write the proportion equation
   78.42 : 108.18 = 53.88 : x
2. Step 2: Convert to fraction form
   78.42/108.18 = 53.88/x
3. Step 3: Cross multiply
   78.42x = 108.18 × 53.88
4. Step 4: Simplify right side
   78.42x = 5,828.74
5. Step 5: Solve for x
   x = 5,828.74/78.42
6. Step 6: Final answer
   x = 74.33