Very helpful. I love how you demostrate on the bell curve so that I can "picutre" what you are saying. I will probably pass my statistics class because of your videos. Thank you for breaking it down and making it understandable!!!
At 05:57 Is this in chronological steps in order STEP III P(x>1800) STEP IV=p(z score?>2.58) the 2nd equation LINE 2/3 to the last graphed step leading up to next? 1-.9951 as STEP V?
Brilliant, thanks for this. I'm doing revision so I was able to work out the sum at the start when you had the values it up on screen before you went through it and then see if I was right.
This was very helpful. My professor taught this to my class in 2 hours and I still could not understand it. Thank you for making this an easy concept to grasp.
Hi my name is Joshua. I am thinking about taking stats 245 at Northern VA community College. Any suggests on what kinds of problems regarding a scores, probabilities, standard deviations etc..? I would like some help on this subject? Thanks for your help
this is helpful but i am a little stuck trying to draw 2 distributions to compare, the range is 19-24 mean 21.5 standard deviation of 2, then the 2nd drawing needs to show the same range but a mean of 21.8 and standard deviation of 1, i have to compare the 2 and see which set of figures gives better results with average falling towards 22, any help would be incredible
I have checked my textbook and it is mentioned that in questions where we are required to find probability of between X and y like part c of your question, we have to add these two values. However you have mentioned to subtract these two values.
Could be true is your z table only gives you the area to the mean. Some tables do that. The table I am using gives the area to the left of the number. Your book may be using a different table than mine. Below is a link to a video I created on how to read the two different tables. th-cam.com/video/BItUZISCkpo/w-d-xo.html
@@crowsmathclass No it's not for the table.. I guess my textbook is using different concept and I am confused whether to subtract or do the addition in the end, if you could help. Your vedio is very helpful for me
I think if you watch the video I linked in my previous comment it will help you understand better. I go into a little more detail of when to add and subtract. Just make sure you watch both methods and then you
There is one more question. In some questions of normal distribution we are require to find the SD value through = SD/√N. But in some questions we are directly putting the values of SD in the question like you did. How we can differentiate between the two questions.. like when we should directly put the SD value in the question and when by the above formula.
Tnx Sir. In the first problem, letter "a", if I want to know exactly how many bulbs have 1800 lumens?( Z score = 2.58). How do I calculate that? I don't look for areas. Tnx again.
when i tried for solving the probability of two values i tried to follow what you have done in problem c but the result of my computation is negative. is it allowed to have a negative value for area after subtracting the 2 values, the one w/ between? thank you so much
Why did you subtract the result of problem a to 1 (more than) while in b you don’t do the subtraction thing? Thank you so much. The given problem to us really confuses me a lot
and what if there's no definite value unlike 1800, i mean if it just says for example what is the probability that 50 of 100 watt lightbulbs will have a brightness more than the average brightness of 1640 lumens?
May be a stupid question, but I need to understand this for my MBA that I'm starting. Why in the first problem is it subtracted from 1, but in the second part it's simply the Z table without subtracting from 1? I think I know the answer, but would like to confirm. Thanks!
@@crowsmathclass Sorry to bother once more, but how do you determine when to subtract from one based upon the question? For instance, I missed a lot of my questions because I didn't subtract with 1, but got some right by not doing so. How do I know when to subtract 1 from n? Is this understanding when a problem is dealing with the population as opposed to a sample? Sorry, my MBA is online, I have two degrees and swore I'd never do anything dealing with numbers again..., so here I am, lol. Thank you so much for any info you can provide!
Assume that 21-year-old men's heart rates at rest are normally distributed with a mean of 63 beats per minute and a standard deviation of 10 beats per minute. If 600 men are examined, how many would you expect to have a heart rate of less than 68?
Great video. But I got a question. We're comparing how far or close the sample mean is relative to the population mean. The distance to either side of the population mean is 0.5000. If we're comparing the sample mean with the population mean, which has a z-value score of 0, why we're taking the whole area under the curve while calculating less than or greater than areas under the curve from the population mean? Shouldn't we be calculating areas under the curve relative to the population mean (z-value = 0), not the whole area under the curve?
i watched this video through out the whole night struggling to understand it just to realize that you are a great teacher. thank you mr steve
Thank you. Glad it helped.
So simple and direct explanation. This is much better than listening to my professor for 2 hours every MWF.
Glad it helped.
I was struggling to understand the probability for weeks, and now I understand it..
I’m really thankful for you & I appreciate your efforts!
Very helpful. I love how you demostrate on the bell curve so that I can "picutre" what you are saying. I will probably pass my statistics class because of your videos. Thank you for breaking it down and making it understandable!!!
Literally saved my soul! Thank you for making it so easy.
You’re welcome. Glad it helped.
6 years later you're still helping students thank you sir
You’re welcome. Thanks for watching.
I had no understanding of this topic until I watched this video... this helped me a whole lot, thank you.
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All my misunderstandings from class and several other TH-cam videos were cleared in one 🙏🏽♥️ Thank you so much
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this just saved my math grade thank you , you are a blessing
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you have save my life i have exam on statistic intwo days and i dont even understand but now i understand it thanks to you
You’re welcome. Good luck on your test.
Thank you for this video! It helped me so much for reviewing for my AP Stats Exam. I believe that I will do so well on the exam thanks to you!
You’re welcome. Glad it helped. Good luck on your exam.
Thank you for helping me understand this. I have NOT been able to grasp this concept before your video!
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you know how to make it really really simple, thank so much heyy
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Man you are the reason behind my additional 6 marks. God bless you 😇😇
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Omg! I’m following along but plugging in my homework variables…TWO problems correct in a row after WEEKS of being stuck!!! Thank you so much!!
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You made this topic so much easier to understand! Thanks so much
You’re welcome.
well, thanks for the video
you really have a different style from the other teachers
batuhan karabacak Glad it helped.
THIS IS EXACTLY WHAT I NEEDED. NO BS VIDEO!!!!
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Super helpful, broke this concept down really easily for me. Appreciate the help
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Lots of love from India.Thank u for making this topic so simple and easy to understand.
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you’re better than my teacher i swear. thank you, you make it easier to solve :))
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you are the best, am writing in the evening my exams. God bless you💓💓.
Thank you. Good luck on your exam.
I like how your southern accent shows up from time to time
⁵⁵⁵55⁵
At 05:57
Is this in chronological steps in order
STEP III P(x>1800)
STEP IV=p(z score?>2.58)
the 2nd equation
LINE 2/3 to the last graphed step leading up to next?
1-.9951 as
STEP V?
Thank you so much, you saved me. Also you're accent is relaxing.
You’re welcome. Thank you for the comment.
Thank you for making this so simple and easy to understand 🙏
Thank you , sir.My teacher has explained this topic well, but I have had some problems with that lesson, albeit I got cleared after this awesome video
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Excellent teaching, important also are your examples, that have an impact in real life problems.
Thank you.
New subscriber here. This video helped me a lot. Many thanks.🙏🏾
You’re welcome. Thank you for the sub.
Thanks Steve! Your explanation was just lucid and it helped a lot.
Thank you for the comment. Glad it helped.
Great Video didn't mind how long it was because it was well explained. I have similar problems and this worked me through them.
Thank you. Glad it helped.
Excellent video. Very informative, as usual. Keep up the videos , please.
Thank you.
You are a lifesaver!!! Thanks a lot... God bless You ❤️💌
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Mr. Steven Crow I hope you have an amazing rest of your life
Thank you. You also.
This was really really good that you! Got an exam tmrw and you really helped :3..also i love your voice 😋
Thank you. Glad it helped. Good luck on your test.
Best Video on Normal Distribution :) Thank you so much.
Thank you.
Brilliant, thanks for this. I'm doing revision so I was able to work out the sum at the start when you had the values it up on screen before you went through it and then see if I was right.
You’re welcome. Glad it helped.
Loved the video! Been struggling with this concept for a bit now, but your video made it super easy to learn!
Thank you. Glad it helped.
this saved me from leaving my module blank before submission 😌 tysm!
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Thank you Thank you Thank you. You explained this very well and with such great patience. Really helped a lot.
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great teaching voice was able to follow along and ultimately grasp the subject. Thanks ALOT!
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wonderful explanation.....jus helped me in Africa ryt now
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Thank you so much,sir.This video saved my semester final.
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it is very helpful. you explained it really well and a lot more simplier than the module and other vids about it
Thank you. Glad it helped.
This helped me a lot. Thank you, sir.
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It has helped me by remembering high school statistics of approximating to binomial.
so helpful! not too long at all, thank you very much mr crow!
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Thank you so much for this video, you did a great job
Thank you
Wow! You're a live saver! Thank u so much! It helped me a lot!!!!!
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Wow, this helped a lot!! You made it very easy to understand. Thank you!!
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Very clear and easy to follow, thank you so much :)
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Powerful presentation ❤
This is awesome, thank you so much tutor 🙏 it really helped
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Thankk yoouuu so much , I do take lectures for 2 hours but your 16.39 are much better
Thank you. Glad the video helped.
I just want to say thank you so much this helped me so much understand
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Finally Something I Was Looking FOR !!!!!! THANKS
You're welcome. Glad it helped. Thanks for the comment and watching.
This was very helpful. My professor taught this to my class in 2 hours and I still could not understand it. Thank you for making this an easy concept to grasp.
Thank you. Glad it helped.
Hi my name is Joshua. I am thinking about taking stats 245 at Northern VA community College. Any suggests on what kinds of problems regarding a scores, probabilities, standard deviations etc..? I would like some help on this subject? Thanks for your help
Very insightful indeed.Thank for the informative video and easy way of dispensing knowledge.
You’re welcome. Glad it helped.
this is helpful but i am a little stuck trying to draw 2 distributions to compare, the range is 19-24 mean 21.5 standard deviation of 2, then the 2nd drawing needs to show the same range but a mean of 21.8 and standard deviation of 1, i have to compare the 2 and see which set of figures gives better results with average falling towards 22, any help would be incredible
Very well explained. Thank you.
You’re welcome. Glad it helped.
Why we didn't minus b value from the table with area?
Very good Video ❤️ I rarely comment but this video deserves 💯
Thank you. Glad it helped.
Thank u for your excellent explanation 😀
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Hello, which software are you using? It is amazing
One note.
So simple explanation . Thanks Steve
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Awesome explanation
tmr i have my math probability exam.. God I hate maths so much 🥲
Thank you. Good luck on your exam.
Great video very clear 👍
Thank you.
Nice video of the year👌👌
Thank you.
It has really helped me n i am grateful for this info
Thank you for the comment. Glad it helped.
Could you do a video about questions were they don't give you the mean or standard deviation?
(btw this vid was great help thanks.)
Thank you for this vedio GOD BLESS♥️✨.
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Thank You, Sir. From Bangladesh.
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thanks for this clear and precise explanation of calculating probability
You’re welcome. Glad it helped.
Thank you so much
I have an exam
It helps me a lot
You’re welcome.
I have checked my textbook and it is mentioned that in questions where we are required to find probability of between X and y like part c of your question, we have to add these two values. However you have mentioned to subtract these two values.
Could be true is your z table only gives you the area to the mean. Some tables do that. The table I am using gives the area to the left of the number. Your book may be using a different table than mine. Below is a link to a video I created on how to read the two different tables. th-cam.com/video/BItUZISCkpo/w-d-xo.html
@@crowsmathclass No it's not for the table.. I guess my textbook is using different concept and I am confused whether to subtract or do the addition in the end, if you could help. Your vedio is very helpful for me
I think if you watch the video I linked in my previous comment it will help you understand better. I go into a little more detail of when to add and subtract. Just make sure you watch both methods and then you
There is one more question. In some questions of normal distribution we are require to find the SD value through = SD/√N. But in some questions we are directly putting the values of SD in the question like you did. How we can differentiate between the two questions.. like when we should directly put the SD value in the question and when by the above formula.
Sounds like you may be approximating binomial using the normal distribution.
Super helpful video. Understood everything!
Thank you. Glad it helped.
Tnx Sir. In the first problem, letter "a", if I want to know exactly how many bulbs have 1800 lumens?( Z score = 2.58). How do I calculate that? I don't look for areas. Tnx again.
Look at the formula of Z. Where
Z= (x-u)/ó
You would just plug everything in to the z formula and solve for x.
when i tried for solving the probability of two values i tried to follow what you have done in problem c but the result of my computation is negative. is it allowed to have a negative value for area after subtracting the 2 values, the one w/ between? thank you so much
Area will always be positive.
Why did you subtract the result of problem a to 1 (more than) while in b you don’t do the subtraction thing? Thank you so much. The given problem to us really confuses me a lot
Excellent explanation, thank you
Thank you.
sir? can i just ask what if there was more than 20 of 100 watt light bulbs in the problem? will the probability stay the same?
and what if there's no definite value unlike 1800, i mean if it just says for example what is the probability that 50 of 100 watt lightbulbs will have a brightness more than the average brightness of 1640 lumens?
Man you are a saviour!!!!
Glad it helped.
Hi, where'd you find the table at 5minutes?
The table comes with your book or you can google and find one
Steve Crow thanks! I tried googling it and it isn’t the same as the table you referenced. Is it okay to use a different one?
Yes. Some tables look different.
you have simplified it Steve. i am ready for exams.
Good luck on your exam.
thank u sm! i hope i'll pass the exam.
You’re welcome. Good luck on your exam.
what is the app you used to make for this video i need to use this app for may performance task
I am using one note to write on and camtasia to record my screen. I use a surface book.
May be a stupid question, but I need to understand this for my MBA that I'm starting. Why in the first problem is it subtracted from 1, but in the second part it's simply the Z table without subtracting from 1? I think I know the answer, but would like to confirm. Thanks!
The table gives answer to the left. If we want answer to the right we need to subtract from 1.
@@crowsmathclass Sorry to bother once more, but how do you determine when to subtract from one based upon the question? For instance, I missed a lot of my questions because I didn't subtract with 1, but got some right by not doing so. How do I know when to subtract 1 from n? Is this understanding when a problem is dealing with the population as opposed to a sample? Sorry, my MBA is online, I have two degrees and swore I'd never do anything dealing with numbers again..., so here I am, lol. Thank you so much for any info you can provide!
@@crowsmathclass I watched some more videos and now I understand! Thank you!
excellent and easy to understand... thank you very much
You’re welcome. Glad it helped.
well done you are such a life saver
Thank you. Glad it helped.
in b, Why didn't you subtract the value you got on standard table from. 1?
Because it was asking for less than.
Thanks for sharing this helpful video
You’re welcome. Glad it helped.
Can we use your table that you use to find z values? That's more easier.
Yes. You may need to ask your teacher.
thank you! excellent explanation. the 1 - z value percentage was key for me.
Thank you. Glad it helped.
Assume that 21-year-old men's heart rates at rest are normally distributed with a mean of 63 beats per minute and a standard deviation of 10 beats per minute. If 600 men are examined, how many would you expect to have a heart rate of less than 68?
Great explanation! Thank you for your contribution!
Thank you for watching. Glad the video helped.
Great video. But I got a question. We're comparing how far or close the sample mean is relative to the population mean. The distance to either side of the population mean is 0.5000. If we're comparing the sample mean with the population mean, which has a z-value score of 0, why we're taking the whole area under the curve while calculating less than or greater than areas under the curve from the population mean?
Shouldn't we be calculating areas under the curve relative to the population mean (z-value = 0), not the whole area under the curve?
Thank you very much ! It’s help a lot 💜
You're welcome. Glad it helped.
You saved my day. Thank you so much!
You’re welcome. Glad it helped.
Wait would P(x > 1800) = 1 - P( z > 2.58)?
he made a mistake but no one realized it.
Thank you so much
This was super helpful ❤️
You’re welcome. Glad it helped.