computer algorithms for statistical calculations

Normal Distribution is always centered around the average value. The left and right end of the curve represents the probability of an observation occurring least likely or uncommon scenario whereas the mid-section of the curve represents the most likely occurring events within a given population. The y-axis represents the relative probability of observation from least likely to most likely. Normal or Gaussian distribution is often described as “bell-shaped-curve” because of its symmetric curve that resembles a bell. Facts regarding the data involved can be presented by descriptive analysis, however, any kind of generalization or conclusion is not possible. It helps in understanding the basic features of the data by summarizing them in a numerical or graphical way. Helps to generalize, conclude and predict a bigger population 12. It involves mathematical estimates that allow us to infer on a pattern or trend based on the sample data sets of a larger population. Note: Skewness is 0 for symmetrical or normal distribution. Depending on whether the left or right tail is skewed for given data distribution, skewness is classified into Positive and Negative skewness as illustrated below Skewness gives us a measure of distortion from symmetry (skew).

Due to this IQR can also be used to detect outliers in the given data set IQR gives us an idea where most of the data points lie contrary to the range that only provides the difference between the extreme points. Q3: middle value in the second half of the ordered data points.Q1: middle value in the first half of the ordered data points.Quartiles are the numbers that divide the given data points into quarters and are defined as below With extreme high and low values, the range can be misleading, in such cases interquartile range or std is used 9. Rangeĭifference between the highest and lowest observations within the given data points. A higher number of Standard Deviation indicates that data is more spread. Standard Deviation measures how spread out the numerical values are. The difference is squared to not cancel out the positive and negative values. Variance is the averaged squared difference from the Mean. There can be more than one mode or none depending on the occurrence of numbers. The mode is the most frequent number present in the given data. In case of even observations, the median is an average value of 2 middle numbers 5. Median is the middle value when the given data are ordered from smallest to largest.

Computer algorithms for statistical calculations