Finding the Fourth Proportional to 78.05, 116.91 and 61.79

Step by Step Solution

1. Step 1: Write the proportion equation
   78.05 : 116.91 = 61.79 : x
2. Step 2: Convert to fraction form
   78.05/116.91 = 61.79/x
3. Step 3: Cross multiply
   78.05x = 116.91 × 61.79
4. Step 4: Simplify right side
   78.05x = 7,223.28
5. Step 5: Solve for x
   x = 7,223.28/78.05
6. Step 6: Final answer
   x = 92.55