Astore had 235 mp3 players in the month of january. every month, 30% of the mp3 players were sold and 50 new mp3 players were stocked in the store.
which recursive function best represents the number of mp3 players in the store f(n) after n months?
f(n) = 0.7 × f(n − 1) + 50, f(0) = 235, n > 0
f(n) = 237 − 0.7 × f(n − 1) + 50, f(0) = 235, n > 0
f(n) = 0.3 × f(n − 1) + 50, f(0) = 235, n > 0
f(n) = 237 + 0.7 × f(n − 1) + 50, f(0) = 235, n > 0

Q.1 dr. frank needs to choose 3 students from her advanced biology course to attend a conference in hawaii. the course has 40 students. which of the following methods could dr. frank use to choose a simple, random sample of 3 students? select all that apply. 1 dr. frank could have the students line up from shortest to tallest, then use her birthdate, 2/5/39, to select 3 students from the line (the 2nd student, the 5th student, and the 39th student). 2. dr. frank could upload her class roster into a spreadsheet and use a ranom-number generating function to produce 3 random numbers. the students whose names are located in the rows with these 3 numbers on the spreadsheet would be chosen. 3. dr. frank could choose the students with the 3 highest grades in the class. 4. dr. frank could count to three, then the first students to come to the front of the classroom and grab a golden ticket from her hand would be selected. 5. dr. frank could ask all students to write their name on a card, place all of the cards in a hat, shake the hat, and then pull 3 cards out from the hat. the students whose names appear on those 3 cards will be selected. 6. dr. frank could ask for volunteers to go to the conference, then choose the first 3 students who raise their hands. q2. now, choose one of the methods that you did not select and explain why this method would not result in a simple, random sample: