# The Normal Distribution and the 68-95-99.7 Rule

The Normal Distribution and the 68-95-99.7 Rule. In this video, I talk about the normal distribution and what percentage of observed values fall within either 1, 2, or 3 standard deviations from the mean. One specific example is discussed. For more free math video, visit http://PatrickJMT.com

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19 replies
1. sean says:

Great video saved my ass

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2. anabel0530 says:

would a score of say 120 be 1 or 2 standard deviations away? do you go by lines or by sections?

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3. Uyen Nguyen says:

Thank you for the video
Its very helpful

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4. Katharine Mansfield says:

Thank you! This was so helpful!

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5. sastrula says:

THANK YOU SO MUCH!!!!

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6. Patrick Clinton says:

Thanks dude!!

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7. Erika Harris says:

Excellent explanation! Now if the question was: What percentage had an IQ between 115 and 55? How would you go about solving that?

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8. karan sharma says:

Thats fantastic buddy, thank you. Quick question – so lets say in your example Z scores is coming 1.8, which means 1.8 standard deviation above/below the mean. But how would we put this into confidence interval ? For instance, i know 1 SD means 68%, 2 SD means 95%….but how would we put 1.8 SD into a confidence interval ?

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9. Mia Wills says:

Thank you!! This was very helpful.

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10. JPoqz says:

Why does not 100% of the data always fall within 3 standard deviations of the mean?

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11. Basheer Oudah says:

thanks

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12. Dr. Aujaiha says:

man you are good!!! thankyou so much:)

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13. SmashBrosBrawl says:

What's your IQ patrick

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14. Madan Mohan says:

Good One — Thank YOu Very much

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15. Rachel Satterfield says:

nice thanks

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16. Murathan Çakıroğlu says:

Thank you that was very helpfull:)))))

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17. Alex Cole says:

This makes no sense at all, you don't even have a data set to work with.

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18. Marielle Rivera says:

OMG!!!! I UNDERSTAND IT!!!
HE EXPLAINED SO DAMN WELL!!!!!

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19. xMyShatteredDreams says:

Thanks so much for this easy explanation!

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