Math 146 Statistics - Miscellaneous Study Information for FINAL EXAM

What is the test statistic?

A test statistic is a random variable that is calculated from sample data and used in a hypothesis test to determine whether to reject the null hypothesis. Examples are t values and z values.

Define 'SE mean'

*Standard error* (or SE) is the approximate standard deviation of a statistical sample population. Standard error is a statistical term that measures the accuracy with which a sample represents a population. In statistics, a *sample mean* deviates from the *actual mean of a population*; this *deviation is the standard error*.

Two Independent Samples - General Hypothesis Testing Symbols and Their Meanings

*y1, y2* are the sample means of the samples from population 1 and population 2 respectively. *s1, s2 are the sample standard deviations of the samples from population 1 and population 2 respectively. *n1, n2* are the sample sizes of the two samples.

What is being assessed when Z, T and P values are used?

General Hypothesis Testing

What is the P value?

The P value, or calculated probability, is the probability of finding the observed, or more extreme, results when the null hypothesis (H 0) of a study question is true - the definition of 'extreme' depends on how the hypothesis is being tested.

Define absolute value

The absolute value is used often in probability and statistics and is a number's positive distance from zero on the number line. In other words, it can't be negative. The absolute value of -3 is 3, because it's three spaces from zero (mean) on the number line.

Confidence Levels vs. Significance Level

The confidence level is equivalent to 1 - the alpha level. So, if your significance level is 0.05, the corresponding confidence level is 95%.

What different types of values are used when determining whether to reject or fail to reject the null hypothesis?

z value t value p value

Define df

Degrees of Freedom (sample size - 1) For example, if n = 30, then df = 29