# Z score vs Z test

I got a bit confused, as Z-score, the standardised value calculation is: x-u/std.

the formula in the video is actually the Z test itself: x-u/std error

so i wonder if the term Z score is used properly in the video regarding the result of the Z test calculation or where did my understanding slip?

Hello Peter!

Thanks for reaching out!

As you pointed correctly, you can calculate the z-score you divide the difference between the value for which you want to calculate the Z-score minus the the mean of the population by the standard deviation of the population.

But when you calculate the Z-test the calculation also incorporates the number of obeservations. So the denominator is different as you can see in the video at 4.06 minute.

Best,

The 365 Team

Thank you for the quick response.

yes of course, my confusion comes from that the video constantly call the Z test result Z score like at 5:45

let me use this opportunity to gratulate for this section. it made a lot of logic easy like applepie. very rare, thank you