Of the 300 television sets sold at an electronics store last month, 90 were flat screen TV's. What is the ratio of flat-screen TV's to other TV's sold last month? I don't know how to do this. I would appreciate some help. thanks!!

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. the design of the study justifies the assumption that the sample can be treated as a simple random sample. use the data to construct a 99% confidence interval estimate of μ, the mean duration of game play. 4028 4316 4816 4650 4036 5010 4833 4331 4307