List A consists of at least two different values and contains only pos
[#permalink]
27 Mar 2021, 12:46
We can solve this problem by trying to come up with counterexamples for each of the statements.
I. "The range of list A is twice as big as the median of list A." CE: {30, 150, 330}. The median is 150 and the range is 300, which is double the median. (I) can be true.
II. "The variance of list A is less than the standard deviation of list A". CE: Imagine a list with nine hundred ninety-nine terms of 30 and one term of 60. The variance will be 908.91/1000, which is less than one, so the standard deviation will be larger than the variance. (II) can be true.
III. "The median of list A is the square of an integer but not an element in list A". CE: {60, 900, 930}. 900 is the square of 30, but 30 is not in the list. (III) can be true.
Since none of the statements cannot be true, (A) is the correct answer.