Finding the Fourth Proportional to 6.99, 10.52 and 5.31

Step by Step Solution

1. Step 1: Write the proportion equation
   6.99 : 10.52 = 5.31 : x
2. Step 2: Convert to fraction form
   6.99/10.52 = 5.31/x
3. Step 3: Cross multiply
   6.99x = 10.52 × 5.31
4. Step 4: Simplify right side
   6.99x = 55.86
5. Step 5: Solve for x
   x = 55.86/6.99
6. Step 6: Final answer
   x = 7.99