Finding the Fourth Proportional to 89.74, 123.78 and 56.93

Step by Step Solution

1. Step 1: Write the proportion equation
   89.74 : 123.78 = 56.93 : x
2. Step 2: Convert to fraction form
   89.74/123.78 = 56.93/x
3. Step 3: Cross multiply
   89.74x = 123.78 × 56.93
4. Step 4: Simplify right side
   89.74x = 7,047.10
5. Step 5: Solve for x
   x = 7,047.10/89.74
6. Step 6: Final answer
   x = 78.53