define terms Arithmetic mean Mode sample variance null hypothesis median alternative hypothesis P(z>a) range standard normal distrubution Solution Arithmetic mean: often referred to as simply the mean or average when the context is clear, is a method to derive the central tendency of a sample space. --------------------------------- --------------------------------------------------------------------- Mode : is the value that occurs most frequently in a data set or a probability distribution ------------------------------------------------------- ----------------------------------------------- sample variance: is the natural measure of the center of the random sample. -------------------------------------------------------------------------------------------- ---------- null hypothesis: typically corresponds to a general or default position. ------------------- ----------------------------------------------------------------------------------- median: is described as the numerical value separating the higher half of a sample, a population, or a probability distribution, from the lower half. ---------------------------------------------------------------------------- -------------------------- alternative hypothesis: is a statement of what a statistical hypothesis test is set up to establish. ------------------------------------------------------------------------------------------ ------------ range: the difference between the highest and the lowest values in a set ---------------- -------------------------------------------------------------------------------------- standard normal distribution: is a normal distribution with zero mean ( mu=0 ) and unit variance ( sigma^2=1 ).