Finding the Fourth Proportional to 78.71, 108.61 and 51.07

Step by Step Solution

1. Step 1: Write the proportion equation
   78.71 : 108.61 = 51.07 : x
2. Step 2: Convert to fraction form
   78.71/108.61 = 51.07/x
3. Step 3: Cross multiply
   78.71x = 108.61 × 51.07
4. Step 4: Simplify right side
   78.71x = 5,546.82
5. Step 5: Solve for x
   x = 5,546.82/78.71
6. Step 6: Final answer
   x = 70.48