Common Symbols Practice

x-bar, p, p hat, mu review

• • x̄ (X-bar)= this refers to the MEAN of the SAMPLE you took. If you make a guess at what the mean is in the whole population you have to use μ instead of x̄ . an example of how you would label your SAMPLE mean would be: x̄=35.7 points

  • μ (mu)= this is the mean of the POPULATION. This is used when you are describing the population as a whole, or when you are guessing at an average of the whole population. You may not know the actual mean, but you still use μ to describe it. An example of how you would label your mean of the POPULATION would be: μ=65 points

  • p= this refers to the population proportion, which is the part of the POPULATION that did what you want. example; p= 82%

  • p̂ (p hat)= This is the proportion of the SAMPLE that did what you were looking for. An example would be: p̂= 89%

P-Value= p-value is based on an imaginary set of data centered around your assumed hypothesis.The p-value represents your chance to have obtained a sample as “extreme”, “low”, or “high” as you got assuming that your null hypothesis value is correct.