Finding the Fourth Proportional to 83.98, 126.17 and 78.38

Step by Step Solution

1. Step 1: Write the proportion equation
   83.98 : 126.17 = 78.38 : x
2. Step 2: Convert to fraction form
   83.98/126.17 = 78.38/x
3. Step 3: Cross multiply
   83.98x = 126.17 × 78.38
4. Step 4: Simplify right side
   83.98x = 9,889.20
5. Step 5: Solve for x
   x = 9,889.20/83.98
6. Step 6: Final answer
   x = 117.76