Four buses carrying 157157 high school students arrive to montreal. the buses carry, respectively, 3636, 4545, 3030, and 4646 students. one of the studetns is randomly selected. let xx denote the number of students that were on the bus carrying this randomly selected student. one of the 44 bus drivers is also randomly selected. let yy denote the number of students on his bus. compute the expectations and variances of xx and yy:

In new york city at the spring equinox there are 12 hours 8 minutes of daylight. the longest and shortest days of the year very by two hours and 53 minutes from the equinox in this year the equinox falls on march 21 in this task you use trigonometric function to model the hours of daylight hours on certain days of the year in new york city a. what is the independent and dependent variables? b. find the amplitude and the period of the function. c. create a trigonometric function that describes the hours of sunlight for each day of the year. d. graph the function you build in part c. e. use the function you build in part c to find out how many fewer daylight hours february 10 will have than march 21. you may look at the calendar.