Silly! There are two easy ways you can check the normality assumption- either with a QQ plot or a histogram.
How do I figure out if my data is normally distributed??
The best method is the QQ plot, which graphs the percentiles of a normal distribution against that of the observed data. If your data is normal, it should look like the line y=x, with no strong deviations.
If the data doesn't follow a straight line, or has a lot of outliers, it probably isn't normally distributed!
If you chose to make a histogram, make sure it resembles the shape of the normal distribution! Otherwise, you cannot assume normality.
Ok I get it! I just need to make sure my QQ plot looks pretty straight, or my histogram looks normal- shaped.