HW Review: H3.4-3.5
In a boxplot, potential outliers are points that are more than ___ IQRs from the edges of the box.
1.5
What is the first step to do with potential outliers? A. Investigate further B. Eliminate them from the data set C. Assume there was an error in the sampling process D. Assume there was an error in entering the data
A. Investigate further
In a right-skewed distribution, which of the following is true? A. The mean tends to be greater than the median. B. The mean and median are approximately the same. C. The mean tends to be less than the median. D. None of these
A. The mean tends to be greater than the median.
In a boxplot, the whiskers extend to which of the following? A. To the most extreme values that are not potential outliers B. To the first and third quartiles C. The smallest and largest values in the data set D. None of these
A. To the most extreme values that are not potential outliers
Boxplots are NOT recommended for use with which of the following types of distributions? Bimodal or any multimodal distribution Symmetric Unimodal Skewed
Bimodal or any multimodal distribution
In your own words, describe to someone who knows only a little statistics how to recognize when an observation is an outlier. What action(s) should be taken with an outlier? A. Outliers are the minimum and maximum values observed in a data set. They should be treated as any other value, as the term "outliers" is just another name for the minimum and maximum. B. Outliers are observations that are more than 1.5 interquartile ranges from the median in a data set. They should be looked at in closer context to determine how to treat the values. Sometimes they may be included, but sometimes they are discarded. C. Outliers are observed values far from the main group of data. In a histogram they are separated from the others by space. Outliers must be looked at in closer context to know how to treat them. If they are mistakes, they might be removed or corrected. If they are not mistakes, you might do the analysis twice, once with and once without the outliers. D. Outliers are observed values far from the main group of data. In a histogram they are separated from the others by space. Outliers should be ignored because they can distort any calculations done and are not representative of typical values.
C. Outliers are observed values far from the main group of data. In a histogram they are separated from the others by space. Outliers must be looked at in closer context to know how to treat them. If they are mistakes, they might be removed or corrected. If they are not mistakes, you might do the analysis twice, once with and once without the outliers.
Which measure of the center (mean or median) is more resistant to outliers, and what does "resistant to outliers" mean? A. The mean is more resistant, which indicates that it is easier to calculate when there are outliers present than the median is. B. The median is more resistant, which indicates that neither the number nor the magnitude of outliers has any effect on the calculated value of the median. C. The mean is more resistant, which indicates that it usually changes less than the median when comparing data with and without outliers. D. The median is more resistant, which indicates that it usually changes less than the mean when comparing data with and without outliers.
D. The median is more resistant, which indicates that it usually changes less than the mean when comparing data with and without outliers.
The length of the box in a boxplot is proportional to which of the following? Median Standard deviation Mean IQR
IQR
Which of the following is NOT one of the five numbers needed to make a boxplot? Mean Median The maximum Q1
Mean
When a distribution contains outliers, which of the following is the best choice for a measure of center? Interquartile range Mean Median Standard deviation
Median
In 1994, major league baseball players went on strike. At the time, the average salary was $1,049,589, and the median salary was $337,500. If you were representing the owners, which summary would you use to convince the public that a strike was not needed? If you were a player, which would you use? Why was there such a large discrepancy between the mean and median salaries? Explain If you were representing the owners, you would use the ... to convince the public that a strike was not needed. If you were a player, you would use the ... to convince the public that a strike was needed. The average and median salaries differ so greatly because ...
average salary, median salary, the distribution of salaries is skewed right.
In a boxplot, the vertical line inside the box marks the location of the _______.
median
Because the median is not affected by the size of an outlier and does not change even if a particular outlier is replaced by an even more extreme value, we say the median is _____ to outliers.
resistant
If the mean and the median of a distribution are approximately the same, then the shape of the distribution is likely to be _______.
symmetric