what type of statistics test for hypothesis concerning means is used when standard deviation is unknown​

Adaycare center charges a $75 enrollment fee plus $100 per week. which of the following represents the cost of sending a child to daycare for 14 weeks?

The tuition costs, c, for a local community college are modeled by c(h) = 250 + 200h, where h represents the number of credit hours taken. the local state university has tuition costs, s, modeled by the function s(h) = 300 + 180h. how many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

Find solution of the linear equation y = 2/3x + 1/3