Finding the Fourth Proportional to 67.30, 100.99 and 57.80

Step by Step Solution

1. Step 1: Write the proportion equation
   67.30 : 100.99 = 57.80 : x
2. Step 2: Convert to fraction form
   67.30/100.99 = 57.80/x
3. Step 3: Cross multiply
   67.30x = 100.99 × 57.80
4. Step 4: Simplify right side
   67.30x = 5,837.55
5. Step 5: Solve for x
   x = 5,837.55/67.30
6. Step 6: Final answer
   x = 86.74