Can someone explain how to do this and me

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 .

Which equation represents a direct linear variationa. y=x2b. y=2/5xc. y=1/xd. y=x+3

Millie decided to purchase a $17,000 msrp vehicle at a 4% interest rate for 6 years. the dealership offered her a $2700 cash-back incentive, which she accepted. if she takes all these factors into consideration, what monthly payment amount can she expect? a.$223.73b.$243.25c.$274.61d.$235.51