WEEK 10 quantitative data analysis 2

what are descriptive statistics?

data to describe characteristics of a sample or relationships of variables

what are examples of descriptive statistics?

- how many men are in the sample

- what was the test average for all students

what is regression analysis?

showing the direction and strength of the relationship between variables using an equation

what is a simple regression?

an estimate of the association between two variables. the direction and the strength

what is the regression analysis using this example:

age and income are related. the older someone is, the more income they get

y = A + Bx

A is direction B is strength

Y changes depending on 1 unit increase in x (1 year increase = income increase)

what does the regression analysis for this case tell us?

- predicted income for a particular age

- direction and strength of association

what are inferential statistics?

interpreting data to make predictions and generalizations about the larger population

what 3 things do univariate inferences need?

1. samples drawn from the population

2. a random sample

3. controlling for sampling errors

what do tests of statistical significance show?

if differences of data is real or due to chance

only real if P value is less than .05

what does the margin of error tell us?

how precise our estimate is because there is uncertainty

what does a higher confidence level mean?

the more certain you are the results fall between the margin of error