BESC 3010 CH 4
Which measure of variation is LEAST sensitive to outliers?
IQR
When data are negatively skewed, which measure of variability is most appropriate?
Quartiles (such as the interquartile range)
When open-ended scores are present in the data, which measure of variability is most appropriate?
Quartiles (such as the interquartile range)
For a normal distribution, which measure of variability is most efficient (in the statistical sense)?
Standard deviation
Compared to a mesokurtic distribution, the tails of a leptokurtic distribution...
are longer
What is the range for this data set? 5, 3, 7+, 1, 4
can't be calculated
One good use of the range is to...
check for outliers
For a normal distribution, skewness.
is equal to 0
A narrow distribution that is sharply pointed in the middle and that has many outliers is called...
leptokurtic
What is the degrees of freedom for the sample variance?
n-1
Compared to a mesokurtic distribution, the peak of a leptokurtic distribution is...
narrower and higher
Compared to a mesokurtic distribution, the peak of platykurtic distribution is...
not as high
What are the values of skewness and kurtosis for a normal distribution?
skewness = 0 and kurtosis = 0
What does the symbol \sigma^2 σ^2 stand for?
the population variance
If the formula for the population standard deviation were used with sample data, then result would be...
too small
When scores in a data set are very close to one another, then the variance...
will be close to 0
If scores in a data set are very different from each other, then the standard deviation...
will be high
For a normal distribution, kurtosis is...
0
What is the population variance for the following data? 4, 5, 5, 6
0.5
What is the interquartile range (IQR) for the these data: 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4+
1
What is the sample standard deviation for the following data? 2, 2, 3, 4, 4
1
What is the sample standard deviation for this data set? 3, 4, 2, 4, 7
1.87
What is the IQR for this data set? 6, 4, 6, 6, 1, 6, 3, 4
2.5
What is the population variance for this data set? 4, 1, 6, 1
4.5
What is the range for the following dataset: 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 3, 3, 4, 5
5
What is the range for this data set? 5, 1, 2, 6, 5
5
What does the label "Q2" refer to?
The median score or the 50th percentile
What is the relationship between the standard deviation and the variance?
The standard deviation is the square root of the variance
Which measure of variation is most influenced by outliers?
range
Which measure requires a degrees of freedom calculation?
sample variance