Mr. Dion is the band director at school. He asks students to record how long they have played an instrument. The dot plot shows the data he has recorded. 2 dots on 1, 3 dots on 2, 4 dots on 3, 7 dots on 4, 1 dot on 5, 1 dot on 6. What unit of measure is used in the study. I need this asap.

Acertain group of women has a 0.640.64% rate of red/green color blindness. if a woman is randomly selected, what is the probability that she does not have red/green color blindness? what is the probability that the woman selected does not have red/green color blindness? nothing (type an integer or a decimal. do not round.)