Statistics Chapter 7 (no equations)

Statistics

Numerical value for a sample

Parameters

Numerical value for a population

Point Estimate

We can only ESTIMATE data with statistics; a sample isn’t a perfect reflection of the population.

3 **Similarities** of Z and T Distributions

1. Continuous and never touches the x-axis

2. Symmetric and unimodal

3. Mean=Median=Mode=0

3 **Differences** of Z and T Distributions

1. Family of Curves based on Degrees of Freedom

2. As sample size (n) increases, the T Distribution approaches a standard normal distribution

3. Variance (s) > 1

3 Properties of the χ² Distribution

1. Family of Curves, based on Degrees of Freedom

2. As the D.O.F. number increases, the graph approaches a more ‘normal’ distribution

3. Begins at 0; right-skewed graph