Finding the Fourth Proportional to 83.84, 116.24 and 78.56

Step by Step Solution

1. Step 1: Write the proportion equation
   83.84 : 116.24 = 78.56 : x
2. Step 2: Convert to fraction form
   83.84/116.24 = 78.56/x
3. Step 3: Cross multiply
   83.84x = 116.24 × 78.56
4. Step 4: Simplify right side
   83.84x = 9,131.81
5. Step 5: Solve for x
   x = 9,131.81/83.84
6. Step 6: Final answer
   x = 108.92