Finding the Fourth Proportional to 91.98, 137.82 and 51.42

Step by Step Solution

1. Step 1: Write the proportion equation
   91.98 : 137.82 = 51.42 : x
2. Step 2: Convert to fraction form
   91.98/137.82 = 51.42/x
3. Step 3: Cross multiply
   91.98x = 137.82 × 51.42
4. Step 4: Simplify right side
   91.98x = 7,086.70
5. Step 5: Solve for x
   x = 7,086.70/91.98
6. Step 6: Final answer
   x = 77.05