Recently, the Derma#1 research clinic published a report stating that the regular application of a very popular sunscreen lotion NoTitan might cause some forms of skin cancer. The manufacturer of NoTitan issued an energetic counterstatement asserting that the Derma#1 clinic's conclusions were statistically inconsistent.

Wellbeing pharmacy chain has been selling NoTitan lotion for a long time. The market research department of Wellbeing wants to see what is currently happening with NoTitan lotion demand. The members of a random sample of customers were asked about their willingness to use NoTitan before and after the publication of Derma#1 clinic's report. The answers were provided in form of a score from 0 to 10 (higher score means more willingness). Results for five customers are shown in the following table. The "before" score is matched to the "after" score, and the difference should be calculated. Suppose that it is known that such differences have approximately bell-shaped distribution.

Step 2. Using d ,fill in the last two columns of the table. Sample mean of the differences is d : _ 2 Participant Before After d d_ d (d d) 'I 7 4 | 2 3 1 | 3 63 4 01 5 6 3 | Total | t