If a sample of data has mean of 21 and SD of 3, which of the following values is more than 2.5 SDs from the mean?  Choose one:  A) a. 12  B) b. 13.5  C) c. 17  D) d. 23.5  E) e. 26.5
Value ismore than 2.5SDfrom the mean means that the distance between the mean and the value must be more than 2.5SD=7.5. So the value either &lt; 21-7.5= 
<gadget id="calculator"> 21-7.5</gadget>
<output>13.5</output>
13.5 or &gt;21+7.5=28.5.   a. 12nswer: a. 12.
<result>A</result>
If a sample of data has mean of 21 and SD of 3, which of the following values is more than 2.5 SDs from the mean?