Finding the Fourth Proportional to 51.38, 77.00 and 42.87

Step by Step Solution

1. Step 1: Write the proportion equation
   51.38 : 77.00 = 42.87 : x
2. Step 2: Convert to fraction form
   51.38/77.00 = 42.87/x
3. Step 3: Cross multiply
   51.38x = 77.00 × 42.87
4. Step 4: Simplify right side
   51.38x = 3,300.78
5. Step 5: Solve for x
   x = 3,300.78/51.38
6. Step 6: Final answer
   x = 64.25