Finding the Fourth Proportional to 78.18, 116.82 and 61.02

Step by Step Solution

1. Step 1: Write the proportion equation
   78.18 : 116.82 = 61.02 : x
2. Step 2: Convert to fraction form
   78.18/116.82 = 61.02/x
3. Step 3: Cross multiply
   78.18x = 116.82 × 61.02
4. Step 4: Simplify right side
   78.18x = 7,128.36
5. Step 5: Solve for x
   x = 7,128.36/78.18
6. Step 6: Final answer
   x = 91.18