Explanation for Question 15 From the Math (Calc) Section on the 2018 March Sat
Question 15 says a group of 10 students play a certain game. 2 Every player received a score equal to an integer from one to 10 inclusive 3 for the 10 players. The mean score was four. 4 If more than half of the players received a score greater than five, 5 which of the following is true about the mean score of the remaining players. 6 So we note that the original mean score was four. 7 And now we're taking out all of the highest numbers, 8 all the numbers greater than five from that mean calculation. 9 So when we're taking out the higher numbers, 10 the mean is going to go down because it's an average of all the 11 scores we're inputting, which means that if the original meaning was four and the 12 mean is going to be lower than that when we're taking only the remaining 13 players, that the mean must be less than four, 14 which tells us that a is the correct.