false
They would both increase.
The standard deviation of the population. the standard deviation of the population.
Yes, outliers can significantly affect the standard deviation. Since standard deviation measures the dispersion of data points from the mean, the presence of an outlier can increase the overall variability, leading to a higher standard deviation. This can distort the true representation of the data's spread and may not accurately reflect the typical data points in the dataset.
Yes.
false
They would both increase.
Strictly speaking, none. A quartile deviation is a quick and easy method to get a measure of the spread which takes account of only some of the data. The standard deviation is a detailed measure which uses all the data. Also, because the standard deviation uses all the observations it can be unduly influenced by any outliers in the data. On the other hand, because the quartile deviation ignores the smallest 25% and the largest 25% of of the observations, there are no outliers.
The standard deviation of the population. the standard deviation of the population.
Yes, the mean deviation is typically less than or equal to the standard deviation for a given dataset. The mean deviation measures the average absolute deviations from the mean, while the standard deviation takes into account the squared deviations, which can amplify the effect of outliers. Consequently, the standard deviation is usually greater than or equal to the mean deviation, but they can be equal in certain cases, such as when all data points are identical.
Yes, outliers can significantly affect the standard deviation. Since standard deviation measures the dispersion of data points from the mean, the presence of an outlier can increase the overall variability, leading to a higher standard deviation. This can distort the true representation of the data's spread and may not accurately reflect the typical data points in the dataset.
The median is least affected by an extreme outlier. Mean and standard deviation ARE affected by extreme outliers.
No. A small standard deviation with a large mean will yield points further from the mean than a large standard deviation of a small mean. Standard deviation is best thought of as spread or dispersion.
Yes.
standard deviation is best measure of dispersion because all the data distributions are nearer to the normal distribution.
The choice of numerical measures of center (mean, median) and spread (range, variance, standard deviation, interquartile range) depends on the distribution's shape and characteristics. For symmetric distributions without outliers, the mean and standard deviation are appropriate, while for skewed distributions or those with outliers, the median and interquartile range are more robust choices. Additionally, the presence of outliers can significantly affect the mean and standard deviation, making alternative measures more reliable. Understanding the data's distribution helps ensure that the selected measures accurately represent its central tendency and variability.
The standard deviation is the standard deviation! Its calculation requires no assumption.