DESCRIPTIVE STATISTICS 5

DescriptiveStatistics

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DescriptiveStatistics

Descriptivestatistics can be regarded as numbers that are utilized to describeand summarize any given data. Similarly, data is used in statisticsto refer to information that have been obtained from a survey,experiment, historical records among others(Grant, Ries & Thompson, 2016).

Reliability

Reliabilityis employed in statistics to refer to the overall consistency of ameasure and high reliability is attained when the measure is able toyield similar result when subjected to similar conditions (Grant*etal.,*2016).

Validity

Validityis the scenario where a test measure what it is intended to measureand the measurements, concept and conclusion obtained from suchmeasurements are directly related to the real world (Grant*etal.,*2016).

Bellcurve

Bellcurve is also known as the normal distribution curve, and itcomprises of a large rounded peak that is tapering away at each end.Similarly, the highest point of the cure represents the likely eventsin a series of data, and the possible occurrences are equallydistributed around the possible event(Cramér, 2016).

Figure(1) showing a bell curve (Cramér,2016).

Mean

Sometimeis also known as the arithmetic and it is the average of all numbersthat are located within a data set. The mean is obtained by adding upall quantities in a set and dividing the summation by the total countof numbers (Cramér,2016).

Standarddeviation

Standarddeviation refers to how data are spread from the central point (mean)and high deviation is obtained when the data points are further fromthe mean. The standard deviation can be obtained by getting thesquare root of the variance by estimating the variation between eachdata point relative to the mean (Cramér,2016).

Standardscore

Thestandard score is also known as the Z-score, and it is verysignificant in statics since it allows the calculation of theprobability of a score to happen within a normal distribution.Similarly, it can be utilized to compare two scores that have beenobtained from different normal distribution, and it has a mean ofzero and standard deviation of one (Cramér,2016).

Scaledscores

Scaledscore can be regarded as the result of some transformation that hasbeen applied to the raw score. Scaled score is very important as ithelps in reporting the scores for all examinees on a consistent scale(Bhattacharya, Lin & Patrangenaru, 2016).

T-scores

T-scoreprovides information on how an individual score vary from the averageand the mean is 50 while the standard deviation is 10 (Bhattacharya*etal.,*2016).

Percentiles

Percentilein statistics can be considered as the 100 equal groups that apopulation can be divided with respect to the distribution of valuesof particular variables (Bhattacharya*etal.,*2016).

Conclusion

Oncedata has been obtained from the field, survey or experiment it isimportant to analyze and summarize in a form that would give realmeaning for easy application.

References

Bhattacharya,R., Lin, L., & Patrangenaru, V. (2016). *Coursein Mathematical Statistics and Large Sample Theory*.Springer.

Cramér,H. (2016). *MathematicalMethods of Statistics (PMS-9)*(Vol. 9). Princeton,NJ: Princetonuniversity press.

Grant,A., Ries, R., & Thompson, C. (2016). Quantitative approaches inlife cycle assessment—part 1—descriptive statistics and factoranalysis. *TheInternational Journal of Life Cycle Assessment*,*21*(6),903-911.