A cement mason starts making concrete by mixing 212 pounds of sand to 314 pounds of gravel. The mason uses 414 pounds of sand and gravel to start the concrete. How many pounds of gravel does the mason use?

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 .