Economics 111Lecture 7.2 Quantitative Analysis of Data

Describing Data 1.Center of the Data 2. Spread of the Data

The Relative Positions of Mean, Median and Mode Symmetric Distribution Positively Skewed Distribution Negatively Skewed Distribution

Symmetric Distribution Frequency Points mean = median = mode

Positively Skewed Distribution Frequency Points mode < median < mean

Negatively Skewed Distribution Frequency Points mean < median < mode

Describing Spread of the Data A small value of any measure of dispersion / spread of the data indicates that the data is clustered more closely around the mean.

Measures of Dispersion IRange IIMean Deviation IIIVariance IVStandard Deviation

I Range

II Mean Deviation Mean deviation is the average of the absolute values of the deviations from the mean.

II Mean Deviation

III Variance Variance is the average of the squared deviations from the mean.

III Variance

IV Standard Deviation Standard Deviation is the square root of the variance.

IV Standard Deviation

Summary Statistics (include in the Project) 1.No. of observations 2.Maximum value 3.Minimum value

Summary Statistics (include in the Project) 4. Mean 5. Median 6. Mode

Summary Statistics (include in the Project) 7. Range 8. Mean Deviation 9. Variance 10. Standard Deviation