What conclusion can be determined from the dot plot below?

five dots above 9, 6 dots above 10, 3 above 11, 1 above 12.

a. the median of the data set is 10.

b. the number of observations is 10.

c. the range of the data set is 12.

d. the mean of the data set is 15.

Abank manager wants to encourage new customers to open accounts with principals of at least $2,500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?