the following data shows the frequency of sellers updating a new whatsapp status promoting their product last month.

30, 28, 21, 15, 23, 21, 27, 28, 21, 19, 23, 27, 28, 17, 18

25, 28, 30, 30, 29, 28, 26, 22, 30, 29, 28, 27, 26, 25, 20

i) On average, how frequent are the sellers updating their status promoting their product last months?

ii) Find a 90% confidence interval for a mean.