Finding the Appropriate z Value for the Confidence Interval Formula (Using a Table)

I show how to find the appropriate z value (using the standard normal table) when calculating a confidence interval. The version of the table used in this video gives the area to the left of the z value (and not the area between 0 and z).

For those that use R, below is the R code to find the values (see the video for illustrations).

z value for a 95% interval:
qnorm(.975)
[1] 1.959964

z value for a 75% interval:
qnorm(.875)
[1] 1.150349

[calebhobbs]

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[chmotnk]

Seriously, I've been looking everywhere for someone to explain this to me and you finally successfully taught me it! Thank you so much

[hannahconfino]

I had a 2.5 hour lecture on this subject. You're amazing for putting it so clearly in 5 and a half minutes! Thank you!

[angelsimpson]

That was just amazing.. I was trying to understand this for more than an hour using my textbook but u made it superclear in a few minutes. Thanks a lot!

[robinsparkles]

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[CT-mcsy]

Thank you for being one of the only ones to include how to use the z- table properly in your video!

[mysterio]

My statistics professor massively over-complicates this topic, thank you for explaining it in a clear, concise, way.

[rynoweston]

Thank you.  I've been trying to figure this out for days and your video is a life saver.  

[mountainview]

Thanks so much for the tutorial. Had so much difficulties reading the table. Now I know.

[emadharazi]

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[Staru]

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[realdvgarg]

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[renemartinez]

Best explanation and probably the only one that I could find, excellent job!

[samuelademolaadedoyin]

The explanation in this video is just perfect. Thanks for sharing.

[mwvgvug]

I was confused for a week, and I got it within 2second by watching this!

[Pickett]

Nowhere else has this been explained so clearly. Thank you 🙌🏾

[prosimulate]

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[yogeshadhate]

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[josephjoestar]

I've been looking on how to make sense of this for a while. You helped me out instantly - thanks!

[rojafx]

Too many algebraic terms made me turn the video off when I first watched the video like a week ago, but now I see you did a specific example