Finding the Fourth Proportional to 42.99, 59.31 and 30.69

Step by Step Solution

1. Step 1: Write the proportion equation
   42.99 : 59.31 = 30.69 : x
2. Step 2: Convert to fraction form
   42.99/59.31 = 30.69/x
3. Step 3: Cross multiply
   42.99x = 59.31 × 30.69
4. Step 4: Simplify right side
   42.99x = 1,820.22
5. Step 5: Solve for x
   x = 1,820.22/42.99
6. Step 6: Final answer
   x = 42.34