For the first leg a trip, Fred traveled A miles at speed p. During the second leg, he traveled at a slower speed. There were only two legs in the trip. The entire trip took T hours, and the average speed for the entire trip was V. Do not mark more than one answer in each column.

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