The most frequently occurring value of a data set is called the:. Since the mode is the most frequently occurring data value, it. All of the following are measures of central tendency except the:. Which measure of central tendency would best depict the following data: 10, , , , , and ? When is it best to use the mean, median or mode as a measure of central tendency?
What is Descriptive Statistics? When should measures of location and dispersion be computed from grouped data rather than from individual data values? What are the different types of descriptive statistics? Which descriptive statistics are measures of dispersion? What are descriptive statistics? In what ways can Descriptive Statistics be useful?
What is the difference between statistics and probability? What is the median of the following masses? Which of the following is not a measure of central location? What is the difference between the Ist quartile, the 2nd quartile, and the 3rd quartile?
What is the difference between a "complete sample" and an "unbiased sample"? What is the difference between a sample and a population in statistics? Measures of spread describe how similar or varied the set of observed values are for a particular variable data item.
Measures of spread include the range, quartiles and the interquartile range, variance and standard deviation. When can we measure spread? The spread of the values can be measured for quantitative data, as the variables are numeric and can be arranged into a logical order with a low end value and a high end value.
Why do we measure spread? All vivas related to this topic. This sort of data is: Expressed numerically, and ordered on a scale Interval data: increase at constant intervals, but do not start at zero, eg. Examples: Median is the middle number in a data set that is ordered from least to greatest Mode is the number that occurs most often in a data set Arithmetic mean is the average of a set of numerical values, Geometric mean is the n th root of the product of n numbers Degree of dispersion These describe the dispersion of data around some sort of mean.
Because the difference can be positive or negative and this is cumbersome, usually the absolute deviation is used which ignores the plus or minus sign. Variance : deviation squared Standard deviation : square root of variance Measure of the average spread of individual samples from the mean Reporting the SD along with the mean gives one the impression of how valid that mean value actually is i. Standard error This is an estimate of spread of samples around the population mean.
You don't known the population mean- you only know the sample mean and the standard deviation for your sample, but if the standard deviation is large, the sample mean may be rather far from the population mean. How far is it? The SE can estimate this. Mean absolute deviation is the average of the absolute deviations from a central point for all data.
As such, it is a summary of the net statistical variability in the data set.
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