One Sample z-Test

[DCARA]

Thank you for actually showing the Z table, to me that is the most confusing part. The z table I have is only for the right half of the curve and gives Z values to one decimal place. Helpful video!

[mosesellahi]

For those who confused why we use significance level is 0.05%. A 5% significance level strikes a balance between the risk of Type I errors (rejecting a true null hypothesis) and Type II errors (failing to reject a false null hypothesis). It is a common compromise that is considered reasonable in many scientific disciplines. So it is mostly used if significance level is not given in question.

[bredleemurray]

This is a very smart explanation. I am really lighten up with the understanding of z-test two tail test for 1 sample for mean. Thumbs up.

[charliehendry]

God bless you. I've watched SO MANY videos in the last couple of hours about this exact topic and this is the first one that I was able to understand and apply it to my homework. I love you king <3

[gusfrr]

dude I'm brazilian and my teacher couldn't do in my native language what u've done in a foreign one . I don't know if you're really good of if she's really bad. anyway, thank you so much

[christdiscipleship]

You reject null hypothesis in both cases if the results are greater or lower than critical value...infact we are fail to reject null hypothesis when the z value is greater than critical value..beacause this way it doesn't come into rejection reigon.we will only reject when value is lower.

[yashpmahadevia]

Very simple method of explaining a complex problem

[chelp]

Hi This really helped me understand the material. However I still dont understand the explanation about why 97.5% was used instead of 95%.

[jwest]

Thank you, very clear and easy to understand. Much better than my textbook!

[nancymutuma]

Why didn't we choose an alpha of 0.01 but 0.05?? Please anyone who understands to explain to me.

Thank you

[rosebud]

Ah yes of course thanks! Sorry didn't see Type I and Type II errors there. That makes a lot more sense.

Thanks again for your lectures. I am a distance learner and would not know what to do if I only had my textbook. Really appreciate these.

[HasibullahSahibzada]

It was a nice tutorial, But i didn't understand that why instead of %2.5 of z you selected 1.96 for calculating the body percentage ?  

[SatishPandu-tkqr]

this is the video i am searching excellent explanation

[MegGonzales]

Thank you so much for this video! had a hard time on how to calculate the table value. Thanks to you, finally done with my stat report <3 Thanks for the big help! :)

[im]

Actually there is one confusing thing, as you would expect that 140 lays between 2 and 3 sigmas and your z is not 14.6, but (140-100)/15. Yet formula tells you to divide on sigma/sqrt(n).
The answer is that IQ itself is not normally distributed, the Mu of IQ has normal distribution, and sigma of average is not 15. So the chart in point 3.) is not correct. Correct chart is that you build normal distribution around average number of 140 which has std = 15/sqrt(30) and then you see that Mu=100 lays within 14.6 errors comparing to the statistic 140

[swimmingsong]

very well explained and allowed concept to sink in. thank you. 

[Family_]

Thank you so much Sir for this video.
But small doubt in z test we take large sample problems but here n is 30 that means this is a small sample text

[levinhogaming]

How did the 1.96 came?and the area in the body too

[swaminathans]

@ statslectures: Very nicely explained. Thank you!

[seungtakho]

"now im going to talk about one of the most basic" *breaksdown*