Finding the Fourth Proportional to 83.32, 124.90 and 42.78

Step by Step Solution

1. Step 1: Write the proportion equation
   83.32 : 124.90 = 42.78 : x
2. Step 2: Convert to fraction form
   83.32/124.90 = 42.78/x
3. Step 3: Cross multiply
   83.32x = 124.90 × 42.78
4. Step 4: Simplify right side
   83.32x = 5,343.22
5. Step 5: Solve for x
   x = 5,343.22/83.32
6. Step 6: Final answer
   x = 64.13