Finding the Fourth Proportional to 78.31, 117.37 and 61.99

Step by Step Solution

1. Step 1: Write the proportion equation
   78.31 : 117.37 = 61.99 : x
2. Step 2: Convert to fraction form
   78.31/117.37 = 61.99/x
3. Step 3: Cross multiply
   78.31x = 117.37 × 61.99
4. Step 4: Simplify right side
   78.31x = 7,275.32
5. Step 5: Solve for x
   x = 7,275.32/78.31
6. Step 6: Final answer
   x = 92.91