Finding the Fourth Proportional to 89.86, 123.78 and 70.42

Step by Step Solution

1. Step 1: Write the proportion equation
   89.86 : 123.78 = 70.42 : x
2. Step 2: Convert to fraction form
   89.86/123.78 = 70.42/x
3. Step 3: Cross multiply
   89.86x = 123.78 × 70.42
4. Step 4: Simplify right side
   89.86x = 8,716.59
5. Step 5: Solve for x
   x = 8,716.59/89.86
6. Step 6: Final answer
   x = 97.00