The arithmetic mean and standard deviation of a certain normal distribution are 16.2 and 2.3, respectively. What value is exactly 2 standard deviations less than the mean?	Choices
A) 10.5	B) 11	C) 11.6	D) 12	E) 12.5
Mean = 16.2   Two standard deviations is 2.3 + 2.3= 
<gadget id="calculator">2.3 + 2.3</gadget>
<output>4.6</output>
4.6   There could be two calues for this.   Mean + two standard deviations= 20.8   Mean - Two standard deviations = 11.6   Answer choice has 11.6 and so 11.6 is the answer.
<result>C</result>
The arithmetic mean and standard deviation of a certain normal distribution are 16.2 and 2.3, respectively. What value is exactly 2 standard deviations less than the mean?