STATPRO

• A correlation is a relationship between two variables.  The data can be represented by the ordered pairs (x, y) where x is the independent (or explanatory) variable, and y is the dependent (or response) variable. 
• A scatter plot can be used to determine whether a linear correlation exists between two variables
• The correlation coefficient is a measure of the strength and the direction of a linear relationship between two variables.
• A hypothesis test is a process that uses sample statistics to test a claim about the value of a population parameter. 
• A verbal statement, or claim, about a population parameter is called a statistical hypothesis
• A null hypothesis is a statistical hypothesis that contains a statements of equality.
• A alternative hypothesis is the complement of the null  hypothesis.  It is a statement that must be true if H0 is false and contains a statement of inequality.
• A type I error occurs if the null hypothesis is rejected when it is true.
• A type II error occurs if the null hypothesis is not rejected when it is false.
• The level of significance is your maximum allowable probability of making a type I error.  It is denoted by a, the lowercase Greek letter alpha.