Finding the Fourth Proportional to 89.79, 123.89 and 58.70

Step by Step Solution

1. Step 1: Write the proportion equation
   89.79 : 123.89 = 58.70 : x
2. Step 2: Convert to fraction form
   89.79/123.89 = 58.70/x
3. Step 3: Cross multiply
   89.79x = 123.89 × 58.70
4. Step 4: Simplify right side
   89.79x = 7,272.34
5. Step 5: Solve for x
   x = 7,272.34/89.79
6. Step 6: Final answer
   x = 80.99