BIOL 180 Chapter Notes - Chapter 4: Null Hypothesis, Statistical Hypothesis Testing, Standard Deviation

• School: UW
• Department: Biology
• Course: BIOL 180
• Professor: H E R R O N, J O N

Document Summary

Standard error for a the mean is a quantity that indicates the uncertainty in a calculated mean (i-beams on graphs) Quanti es how con dent you are that the mean you"ve calculated is the mean you"d observe if you did the experiment under the same conditions an extremely large number of times. Sometimes, error bars represent con dence interval of the mean mean. Con dence interval gives an estimated ranged of values that is like to include the population parameter being studied, such as the survival rate of animals after exposure to a pathogen. Calculated from a given set of sample data. A con dence level of 95 percent means that 95 percent of the con dence intervals would include the population parameter. Related to standard deviation, which doesn"t change as a sample size increases. Standard error of the mean (sem) depends on both standard deviation (sd) and sample size.