Complete the following paragraph.
Many firms pay "time and a half" for overtime for any hours beyond worked in any one week. This phrase means that if you work
the basic number of hours, the rate of pay per hour changes.

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 .