Finding the Fourth Proportional to 61.01, 91.58 and 56.78

Step by Step Solution

1. Step 1: Write the proportion equation
   61.01 : 91.58 = 56.78 : x
2. Step 2: Convert to fraction form
   61.01/91.58 = 56.78/x
3. Step 3: Cross multiply
   61.01x = 91.58 × 56.78
4. Step 4: Simplify right side
   61.01x = 5,199.17
5. Step 5: Solve for x
   x = 5,199.17/61.01
6. Step 6: Final answer
   x = 85.23