Finding the Fourth Proportional to 102.86, 141.80 and 89.00

Step by Step Solution

1. Step 1: Write the proportion equation
   102.86 : 141.80 = 89.00 : x
2. Step 2: Convert to fraction form
   102.86/141.80 = 89.00/x
3. Step 3: Cross multiply
   102.86x = 141.80 × 89.00
4. Step 4: Simplify right side
   102.86x = 12,619.05
5. Step 5: Solve for x
   x = 12,619.05/102.86
6. Step 6: Final answer
   x = 122.69