Question

Define:

mean, median, mode, variability, correlation, positive correlation, negative correlation, statistical significance

Answer 1

Mean, Median and Mode are measures of Central Tendency whereas Correlation that includes Positive Correlation and Negative Correlation are measures of Dispersion.

Central Tendency:

Central Tendency gives an idea about the middle range of the data.

Mean:

Mean is the average value. It is obtained by adding all the values in the data and dividing it by the number of values in the data.

Median:

Median refers to the data that is in the middle of the data set. Data is arranged in a particular order eg. ascending order or descending order and the middlemost number in case of an odd-numbered data set or the sum of the average of the two middlemost numbers in case of an even-numbered data set.  

Mode:

Mode refers to the number that occurs the most number of times in a given data set. There can be multiple numbers that occur as Mode in a particular data set.

Dispersion:

Dispersion attempts to measure the variation in the numbers or points in the data set.

Variability:

Variance gives an idea as to how much the numbers or points in the data set are deviating from the mean. A Large Variance indicates that data items or numbers are located far away from the mean whereas Small Variance means the data items or numbers are located nearer the mean.

Correlation:

Correlation is a measure of how the numbers or points in a data set are related to each other in a quantifiable way. Eg. Height and weight relation in females in a particular county can be analyzed to find the relation between the two. Does a taller person weigh more?

Positive And Negative Correlation:

Correlation is related to Covariance. When Covariance is divided by the Standard Deviation of the variables, it is known as Correlation. The value so obtained can either be a positive or negative correlation ranging from +1 to -1. In case a positive value is obtained, it is Positive Correlation which means that a change in one quantity with lead to a change in the other variable in the same direction. Eg. Tall people, in general, weigh more than short people. As height increases, weight increases. When the value so obtained is negative, it is a Negative Correlation which means that a change in one quantity with lead to a change in the other variable in the same direction. Eg. The price of refrigerators increases, the demand for refrigerator falls.