standard daviation

[super_nova]

Q-The arithmetic mean and standard deviation of a certain distribution are 13.5 and 1.5, respectively. what value is exactly 2 standard deviation less than the mean?

a. 10.5
b. 11.0
c. 11.5
d. 12.0
e. 12.5

can anyone clarify me what the question is asking for; specially, the underlined sentence.

[Vivek Goyal]

2 standard deviation less than the mean = 13.5-(2*1.5) = 10.5

OA should be 'A'

[geekybiz1]

Agree with Vivek
10.5 it is.

[chatru]

The answer is "A"

S.D = deviation from the mean
2 standard deviation is = 3
hence the answer is 13.5 - 3 = 10.5

[farooq]

Q-The arithmetic mean and standard deviation of a certain distribution are 13.5 and 1.5, respectively. what value is exactly 2 standard deviation less than the mean?

a. 10.5
b. 11.0
c. 11.5
d. 12.0
e. 12.5

SD 1 = 13.5-1.5 = 12
SD 2 = 12 - 1.5 = 10.5

[arindambanerji]

Has to be A..simple one