R = maximum data value  minimum data value
IQR = Q3  Q1

Use Descriptive Statistics CalculatorEnter the data set as a list of real numbers x_{1}, x_{2}, x_{3} ... x_{N} separated by commas then press "Calculate Descriptive Statistics" and check the data entered. The outputs are:
Possible mistakes to avoid : extra space between digits, two successive commas, comma at the end of the list of the numbers entered, etc .... If you have data values separated by commas and well formated, you may copy and paste them in the text area. The text area to input data can be made much larger by pulling its bottom right hand side. More References and LinksMean and Standard deviation  Problems with SolutionsStandard Deviation Quartiles and box plots Mean and Standard deviation. 