m********9
发帖数: 116 | 1 16. The least accurate statement about measures of dispersion for a distribu
tion is that the:
A. range provides no information about the shape of the data
B. mean absolute deviation will always be smaller than the standard deviatio
n
C. arithmetic average of the deviations around the mean will always be equal
to one
D. variance of a sample with 50 observations is computed by dividing the sum
of the squared deviations from the mean by 49
因为答案的文件里，没有这一题的答案，所以想请教大家该选什么？ | v****b
发帖数: 8 | | m********9
发帖数: 116 | 3 这题我也没有答案，问了其他人说是选B，不过也不确定。。。你确定吗？哪个LOS有？
【在 v****b 的大作中提到】
: 我选C， 应该是0。
| v****b
发帖数: 8 | 4 不清楚LOS, 可能应该选B，但 C 也不对，可能题错了least accurate应该是most
accurate, D 应该是50 而非49，所以改了题后选 A
For example, 1, 3, 5
mean = (1+3+5)/3=3
mean absolute deviation =(3-1)+0+(5-3)/3=1.33 http://en.wikipedia.org/wiki/Absolute_deviation
standard deviation = sqrt[(2*2+0+2*2)/3]=1.63>1.33
For example, 2, 2, 2
mean = (2+2+2)/3=2
mean absolute deviation = 0
standard deviation = 0 | m********9
发帖数: 116 | 5 D 是对的吧，degree freedom应该是n-1=49呀
不清楚LOS, 可能应该选B，但 C 也不对，可能题错了least accurate应该是most
accurate, D 应该是50 而非49，所以改了题后选 A
For example, 1, 3, 5
mean = (1+3+5)/3=3
mean absolute deviation =(3-1)+0+(5-3)/3=1.33 http://en.wikipedia.org/wiki/Absolute_deviation
standard deviation = sqrt[(2*2+0+2*2)/3]=1.63>1.33
For example, 2, 2, 2
mean = (2+2+2)/3=2
mean absolute deviation = 0
standard deviation = 0
【在 v****b 的大作中提到】
: 不清楚LOS, 可能应该选B，但 C 也不对，可能题错了least accurate应该是most
: accurate, D 应该是50 而非49，所以改了题后选 A
: For example, 1, 3, 5
: mean = (1+3+5)/3=3
: mean absolute deviation =(3-1)+0+(5-3)/3=1.33 http://en.wikipedia.org/wiki/Absolute_deviation
: standard deviation = sqrt[(2*2+0+2*2)/3]=1.63>1.33
: For example, 2, 2, 2
: mean = (2+2+2)/3=2
: mean absolute deviation = 0
: standard deviation = 0
| m********9
发帖数: 116 | 6 非常感谢~~
【在 v****b 的大作中提到】
: 不清楚LOS, 可能应该选B，但 C 也不对，可能题错了least accurate应该是most
: accurate, D 应该是50 而非49，所以改了题后选 A
: For example, 1, 3, 5
: mean = (1+3+5)/3=3
: mean absolute deviation =(3-1)+0+(5-3)/3=1.33 http://en.wikipedia.org/wiki/Absolute_deviation
: standard deviation = sqrt[(2*2+0+2*2)/3]=1.63>1.33
: For example, 2, 2, 2
: mean = (2+2+2)/3=2
: mean absolute deviation = 0
: standard deviation = 0
| v****b
发帖数: 8 | 7 According to D, I am not sure here.Maybe it is right with 49. | y***t
发帖数: 644 | 8 Should select B if the question is "most accurate" |
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