Is 9 ft greater than 4 yards

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 .

Two numbers have a sum of -19. one number is x. what expression represents the other number?

Im so bad at fractions they are not my best math thing to work on