Finding the Fourth Proportional to 78.09, 116.91 and 60.81

Step by Step Solution

1. Step 1: Write the proportion equation
   78.09 : 116.91 = 60.81 : x
2. Step 2: Convert to fraction form
   78.09/116.91 = 60.81/x
3. Step 3: Cross multiply
   78.09x = 116.91 × 60.81
4. Step 4: Simplify right side
   78.09x = 7,109.30
5. Step 5: Solve for x
   x = 7,109.30/78.09
6. Step 6: Final answer
   x = 91.04