What pattern do you notice between the numbers 2,3,8 and 63

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 .

Pls brainliest will be awarded if answer is correct

Aphrase is shown read the phrase and give me the answer