OG详解-OG4 数学2 Q24

Choice C is correct. The median of a data set with an odd number of values, in ascending or descending order, is the middle value of the data set, and the range   of a data set is the positive difference between the maximum and minimum values in the data set. Since the dot plot shown gives the values in data set A in ascending order and there are 15  values in the data set, the eighth value in data  set A, 23, is the median. The maximum value in data set A is  26  and the minimum value is 22, so the range of data set A is 26-22, or  4. It’s given that data set B is created by adding  56 to each of the values in data set A. Increasing each of the 15 values in data set A by  56  will also increase its median value by 56 making the median of data set B  79. Increasing each value of data set A by  56  does not change the range, since the maximum value of data set B is  26 +56, or  82, and the minimum value is 22 +56, or  78, making the range of data set B  82-78, or  4. Therefore, the median of data set B is greater than the median of data set A, and  the range of data set B is equal to the range of data set A.
Choice A is incorrect and may result from conceptual or calculation errors. Choice B is incorrect and may result from conceptual or calculation errors. Choice D is incorrect and may result from conceptual or calculation errors.