Concerning a distribution of scores what is the significance

Concerning a distribution of scores, what is the significance of determining basic measures of variability involving the range, standard deviation, and standard error of measurement?

Solution

Range: This gives us the value of the difference between the highest and lowest.

Range helps us to prepare frequency distributions, but cannot be fully relied as middle entries deviations are ignored.

Range can be used to measure outliers and a brief idea about the distirbution

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Std deviation: This is a measure of variation and measured in absolute values as squares of difference of each entry from the mean and then square root is taken. For two data with same mean and no of entries, std deviation gives us an idea about the consistency of the data and the deviations from the mean.

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When large population is estimated from a small sample size, std error of measurement is used as std deviation of the sample

Std error of sample n = std dev/rt n

where n is the sample size