Finding the Fourth Proportional to 83.07, 123.83 and 78.51

Step by Step Solution

1. Step 1: Write the proportion equation
   83.07 : 123.83 = 78.51 : x
2. Step 2: Convert to fraction form
   83.07/123.83 = 78.51/x
3. Step 3: Cross multiply
   83.07x = 123.83 × 78.51
4. Step 4: Simplify right side
   83.07x = 9,722.09
5. Step 5: Solve for x
   x = 9,722.09/83.07
6. Step 6: Final answer
   x = 117.03