Symbols in a Data Table n The size of a data set (sample size) N The size of a data set (population size) Mean The mean (sample mean, population mean μ) of a data set is obtained by adding up all the numbers then dividing by the size of the data set. Std. Deviation (S.D.) A standard deviation (σ) is a measure of how dispersed the data is in relation to the mean. Note: The bigger the SD, the more dispersed the data set.	Data Set: 82, 78, 76, 84, 78, 82 ( X ) in Excel file Sample Size n = =count(data set) Sample Mean ) = =average(data set) Sample S.D. s = =stdev(data set)
Hypothesis Testing Q. Which one is easier and flawless? 1. To prove H1 is true 2. To reject H0 and accept H1 Research Hypothesis (H1): All swans are not white. Null Hypothesis (H0): All swans are white. Note 1: Researchers try to reject H0 and accept H1 rather than trying to directly prove H1 Note 2: H0 always has a symbol with an equal in it. H1 never has a symbol with an equal in it.	Falsification
statistically significant, statistical significance	video
p-value < 0.05 (significance level α) the probability of a misleading conclusion that is the probability of rejecting H0 given that H0 is true or the probability of not rejecting H0 given that H0 is false Q. Which one is H1? Which one is H0? 1. Men are taller than women. 2. Men are not taller than women. Research Hypothesis (H1): Menheight > Womenheight Null Hypothesis (H0): Menheight ≦ Womenheight Note: Q. How can statistics lead to a misleading conclusion? Common ways that statistics can be misleading include selective bias, neglected sample size, faulty correlations, and causations, and the use of manipulative graphs and visuals.	video
Sig. (2-tailed) We want to know whether there is difference between dataset A and dataset B. Sig. (1-tailed) We want to know whether dataset A > dataset B or dataset A < dataset B.	video
df: degree of freedom df = n – 1	video
Independent Sample t-test	video