# How to calculate p-value?

Probability theory and statistics

### How to calculate p-value?

I've got these tests

They show the growth of a plant in mm and I have to test if the growth is inferior to 1.1mm
I think I have to get the p-value from KS test but I'm not seeing how
Attachments
5RSdkqp.jpg (58.71 KiB) Viewed 669 times
Guest

### Re: How to calculate p-value?

Usually the p-value is looked up on a chart on either the T distribution (if n < 30) or the Z distribution if (n ≥ 30). This doesn't give an exact value. Instead an approximate p-value is obtained. This is because to calculate the p-value based on data, it requires a pretty complex calculus equation. Thus, usually in schools, teachers will just have you look up the value on a distribution chart. If you want to find the exact value, you can either do the calculus to solve for it or just use an online https://www.docpid.com/calculators/p-value. All you must do is enter the test statistic, the sample size of the data, the hypothesis testing type, and the significance level value. I see all of those present in your chart above, though you would want to convert the commas to decimal points. I know those are in portuguese form. The sample size is equal to, n = df + 1. The calculator will then compute the accurate p-value.
Guest