3. A class completes a test which is out of 60 marks. The teacher calculates the mean score as 42 and the variance as 25. She decides to convert the scores into percentages by subtracting 10 marks from all the scores, and then multiplying by 2. (a) Find the new values for (i) the mean [2] (ii) the variance [2] An extra student then completes the test late, and scores 30 out of 60. (b) Giving your reasons, state whether this will cause an increase or a decrease in the mean [1] (ii) the variance [1] [Total 6 marks]