Finding the Fourth Proportional to 78.42, 117.56 and 70.83

Step by Step Solution

1. Step 1: Write the proportion equation
   78.42 : 117.56 = 70.83 : x
2. Step 2: Convert to fraction form
   78.42/117.56 = 70.83/x
3. Step 3: Cross multiply
   78.42x = 117.56 × 70.83
4. Step 4: Simplify right side
   78.42x = 8,326.42
5. Step 5: Solve for x
   x = 8,326.42/78.42
6. Step 6: Final answer
   x = 106.18