Finding the Fourth Proportional to 10.01, 15.00 and 3.99

Step by Step Solution

1. Step 1: Write the proportion equation
   10.01 : 15.00 = 3.99 : x
2. Step 2: Convert to fraction form
   10.01/15.00 = 3.99/x
3. Step 3: Cross multiply
   10.01x = 15.00 × 3.99
4. Step 4: Simplify right side
   10.01x = 59.90
5. Step 5: Solve for x
   x = 59.90/10.01
6. Step 6: Final answer
   x = 5.99