Statistics Homework 1 & 2

Descriptive Numerical Summaries • Mean and Median

Mean stands for the average number of the dataset while median is the middle number of the dataset. Mode is the most frequent number shows in the dataset. For the variable sales, the median is 412.75 and mean is 400.29. While the mode is 431.8, we can tell the distribution of the “sales” variable is somewhat left skew.

• Standard deviation and Range Standard deviation is the square root of its variance. It measures how spread out the samples are. Range is the difference between the largest number and smallest number in a dataset. The standard deviation of sales is174.22. The range of sales is 711.2. We can tell the “sales” variable fluctuates dramatically.

• Kurtosis and Skewness Skewness measures symmetry while kurtosis tells if the data is heavy- tailed or light-tailed comparing with standard distribution. The kurtosis of sales is -0.806, this means the dataset has less in tails than the normal distribution. The Skewness of sales is 0.22, which means the data is symmetrical, while the skewness of satisfaction is 0.94, we can tell the data is moderately skewed and the distribution is more like a half-normal distribution.

Sales

Mean 400.2852 Standard Error 16.76391 Median 412.75 Mode 431.8 Standard Deviation 174.2157 Sample Variance 30351.1 Kurtosis -0.80588 Skewness 0.221054 Range 711.2 Minimum 101.6 Maximum 812.8 Sum 43230.8 Count 108

Table 1 Descriptive Statistic Tables