The estimated total cost, y, of a child’s toy is partially based on the number of batteries used, x. The cost of one battery is $0.75. The toy itself costs $12. Which equation represents the situation? y = 12x + 0.75
y = 0.75x + 12
y = 12x – 0.75
y = 0.75x – 12

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 .