Standard deviants: measures of central tendency, measures of dispersion, population versus sample, z-scores and probability. Calculate the mean for every observation ie first observation minus the mean = square the value = new squared value (squaring in order to remove the negative number) Sum all of the squared values to get a new value (sum of squared deviations) Next, divide that value by the sample size (n) minus 1. =53. 5: divide that value by the sample size (n) minus 1. N= 6 the # of values of x. Professor david walters: standard deviation of the x = square root of the variance. Inferences taking one piece of data and using it to interpret another piece of data: sample--a randomly selected part of the population ie the number of soda drinkers in a large population. 5 steps to solve a statistical problem: identify the problem in population, determine the design of the experiment, analysis of data.