# Step 7

# Data Analysis 3

# Inferential Statistics

Inferential statistics perform calculation with your data that will determine differences and relationships. Inferential statistics will perform a calculation that will allow you to say with certainty that a treatment did make a difference, or did not make a difference; whether there is a difference between groups, or no difference between groups; or whether there is a relationship between two things.

For example, a research looking at the effects of an energy drink on running performance: would use an inferential statistic to compare the before energy drink run to the energy drink run and confirm with 95+ percent certainty that the drink did work or did not work.

A further example, a research looking at the difference response of males and females in aerobic performance: would use an inferential statistic to compare males and females scores and confirm with 95+ percent certainty that there is difference between genders or there is not a difference between genders.

Another example, a research wanting to determine a relationship (correlation) between body weight and strength: would use an inferential statistic to determine with 95+ percent certainty that there is a correlation between body weight and strength or there is no correlation between body weight and strength.

However, there are a number of inferential statistics and you need to choose the right one!

You can use one of the parametric inferential test or one of the non-parametric tests.

## PARAMETRIC INFERENTIAL TEST

Think about your choice in step 4, what types of data do you have? You can only use a parametric inferential test if you have ratio or interval data!!

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## NON-PARAMETRIC INFERENTIAL TEST

Think about your choice in step 4, what types of data do you have? You can only use a non-parametric inferential test if you have ordinal or nominal data!!