Answer to Question #275636 in Statistics and Probability for Sehrish

Question

Question # 1

Why do we need to compute the measure of dispersion (variance and standard deviation) even if we have computed the measure of central tendency (mean, median, and mode, etc.)?

Question # 2

What is the difference between Pie Chart and Bar Chart? Why do we use them?

Note:

Answer should be relevant. Irrelevant and unnecessary lengthy materials will not be considered

Answer 1

Question # 1

While measures of central tendency are used to estimate "normal" values of a dataset, measures of dispersion are important for describing the spread of the data, or its variation around a central value. Two distinct samples may have the same mean or median, but completely different levels of variability, or vice versa.

Question # 2

Pie charts show how much each category represents as a proportion of the whole, by using a circular format with different-sized “slices” for different percentages of the whole. Bar graphs use a series of rectangular bars to show absolute values or proportions for each of the categories.

A bar chart is used when you want to show a distribution of data points or perform a comparison of metric values across different subgroups of your data. From a bar chart, we can see which groups are highest or most common, and how other groups compare against the others.

Pie charts make sense to show a parts-to-whole relationship for categorical or nominal data. The slices in the pie typically represent percentages of the total. With categorical data, the sample is often divided into groups and the responses have a defined order.