# Learning Objectives

• Compute and interpret a range, interquartile range, and semi-interquartile range.
• Compute and interpret the variance and standard deviation for a population and sample of data using the definitional formula.
• Compute and interpret the variance and standard deviation for a population and sample of data using the computational formula.
• Explain why the sample variance and population variance are computed differently.
• State the characteristics of the standard deviation and explain the empirical rule.
• Compute the range, variance, and standard deviation using SPSS.