RewarDing FoR CorreCt AnsWer The mean number of stereos sold per day at a store for 7 days was 18. Which statement must be true about the stereo sales at the store?

The store sold 25 stereos for the 7 days.

The store sold 126 stereos for the 7 days.

The store sold 18 stereos on at least half of the 7 days.

The store sold 18 stereos on at least two of the days.