How does carbon dioxide increase the earths tempature

Donald is studying the eating habits of all students attending his school. he samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. he then collects data from the sample. which type of sampling is used? select the correct answer below: systematic sampling convenience sampling stratified sampling cluster sampling

John recently received his semester grades and found that he had failed two courses. he says the reason he failed the two courses is that they were taught by female professors. john believes that women are really not smart enough to teach at the college level. in this example, the female professors are a) spacegoats and being blamed for john's grades b) being discriminatory toward john c) probably not smart enough to teach in a college d) prejudiced against john because he is male

Why was the cumberland gap a good place for a trail