If a certain sample of data has a mean of 15.0 and a standard deviation of 2.0, which of the following pairs contain two values that are each at least 2.5 standard deviations from the mean?	Choose the correct choice from the following.
A) (8.0; 16.5)	B) (8.5; 21.0)	C) (14.0; 26.5)	D) (16.5; 26.0)	E) (21.0; 26.5)
2.5 standard deviation equals to 2.5*2= 
<gadget id="calculator">2.5*2</gadget>
<output>5</output>
5;   2.5 standard deviations from the mean, so5 points, from the mean is the range from {mean-5} to {mean+5}, so from 10 to 20.   The correct answer choice must cover all this range: only answer choice B does this.   Answer: (8.5; 21.0).
<result>B</result>
If a certain sample of data has a mean of 15.0 and a standard deviation of 2.0, which of the following pairs contain two values that are each at least 2.5 standard deviations from the mean?