1. This data shows the pocket money that year 9 pupils receive each week.
E11 -4 £4 3 £9 £10 £6 £4
£3
(a)
Find the mean of the data.

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .