Thank you very much for this video. I struggled a lot with those examples because our teacher never used any examples to explain how everything works and this video helped me to understand how everything works.
I never sat and watched the video, but I sure do love this guy's website link. I was just checking it all out. It's a great interactive refresher, Hands-on Math Course. Free. Thanks from all of us. Joe👌
I went throught this in my data science course and your explanation makes it more clear. I have a question: Why most of your videos are having green background ?
A certain class of students is assessed for mathematical aptitude. The class average is 70% with a standard deviation of 5%. What is the probability of a student scoring 80%? What is the probability of a student scoring 60%? What is the probability of a student scoring between 70% and 85%? What is the probability of a student not scoring above 60%?
Thank you Andy!! I request a clarification though... Q3, while calculating Z2 we got 0.83 However in Q2 we subtracted Z from 1 because we're calculating greater than Then why not in this case?
Good question! I'll try to type a clear answer. I would think of question three as "between" 4.5 and 5.6. The best way to find the between is the look at all the area below 5.6 and then subtract all the area below 4.5, what remains would be the area between the two numbers. Does this make sense?
Question number 3, since there’s a between there. Which means less than and greater than, do we subtract the final answer from 1? Or keep it as it is? Thanks!
Hi. The .8413 represents all the area to the left of the 5.6 observation. The .2033 represents all the area to the left of the 4.5 observation. By subtracting .2033 from .8413 we are left with the area between the two observations. The final answer should be .6380. I don't believe we need to subtract anything from 1. Does this make sense?
Oh, I see what you are saying now. Yes, we could think of it as two separate inequalities a greater than and a less than, "X4.5." But it gets tricky when we need both of them to be true. Any time you see one like 4.5< X
@@ashleyl7608 I looked around online and I can't find any tutorials for your calculator to do this. I know a lot of graphing calculators can do it, but as far as I can tell online, yours doesn't. I could be wrong. If you have a computer, you can google "z-table" and it should provide plenty of them you can use. I hope this helps!
Example two i have got a different value. First my table only reads up to 0.5 so i have to split the area, 0.5 plus the the other area. i dont know where i am missing out coz i have repeated twice and still got 0.5517.
Hello. Thank you for this video. What is the question asks the probability of selecting a score between the mean and a score of 90. If the mean is 80 and standard deviation is 10?
The add or subtract .5 is probably related to a Continuity Correction. It is the adjustment made when a discrete distribution is approximated by a continuous distribution. If you were using the normal distribution to approximate some other distribution, then you would need to use the +/-.5. Hopefully this helps, if not, let me know and I can try to explain further.
The z table always returns the area less than the point. Since question number 2 asked for greater than (>) you want to subtract it from 1. If you do 1- the area less than. It give you the area greater than. I hope this makes sense!
I dont really know how to solve this..I hope someone can help me answer these problems😊 Mean is 72 with standard deviation of 12, find A. Proportion above 90 B. Proportion below 90 C. Proportion between 48 and 95 D. Proportion between 75 and 85 E. Proportion above 55 Thank you in advance❤️😊
yes, as the first number on the table would be the 0. so if you’re looking at, say 1.3, that first number would be 1.30. then 1.31, 1.32, 1.33 and so on.
@@ranasingh8913Thank you for the kind message. Good luck on your test! If you ever need more math practice, I put together a website andymath.com that organizes all my math notes. It's free, I like people to use it!
This is all I’ve needed.... the entire semester.....
I hate my stat professor.
Thank you very much for this video. I struggled a lot with those examples because our teacher never used any examples to explain how everything works and this video helped me to understand how everything works.
Thank you for the kind note. I am glad it helped!
You're such a nice teacher,needless to say . It helped me a lot.
I never sat and watched the video, but I sure do love this guy's website link. I was just checking it all out. It's a great interactive refresher, Hands-on Math Course. Free. Thanks from all of us. Joe👌
Thank you so much! I'm helping my daughter with her summer college course and your video has helped so much.
OMG, our proff just give us an Christmas activity and she nerver thought this. Thank you so much ❤️❤️
Thanks to you of all
With due respect i ask you that how do you find z= -1.67 from .0475?
If 3 things are selected, how would i find the probability that all 3 things exceed a certain value?
I went throught this in my data science course and your explanation makes it more clear. I have a question: Why most of your videos are having green background ?
Best explanation on all of RUclips
A certain class of students is assessed for mathematical aptitude. The
class average is 70% with a standard deviation of 5%. What is the
probability of a student scoring 80%? What is the probability of a student
scoring 60%? What is the probability of a student scoring between 70%
and 85%? What is the probability of a student not scoring above 60%?
Thank you Andy!!
I request a clarification though...
Q3, while calculating Z2 we got 0.83
However in Q2 we subtracted Z from 1 because we're calculating greater than
Then why not in this case?
Good question! I'll try to type a clear answer. I would think of question three as "between" 4.5 and 5.6. The best way to find the between is the look at all the area below 5.6 and then subtract all the area below 4.5, what remains would be the area between the two numbers. Does this make sense?
@@AndyMath yes it does! Wow... Thank you for quick reply!! Best wishes mate :)
@@sirrus1012 Great! Write anytime with math questions, I am happy to help. You can subscribe to find me easily.
Iam here and I found it the channel thanks for your helping us 👑
for number 2, why did you take 1 minus .0918? Is there any rules right here?
Thank you.. you helped me out...
This was so helpful! How would you calculate a probability of an (x greater than or equal to or less than or equal to a value)
Great. I am happy to hear. Let me know if you have any other math questions. I can try to put together a video answering them.
Question number 3, since there’s a between there. Which means less than and greater than, do we subtract the final answer from 1? Or keep it as it is? Thanks!
Hi. The .8413 represents all the area to the left of the 5.6 observation. The .2033 represents all the area to the left of the 4.5 observation. By subtracting .2033 from .8413 we are left with the area between the two observations. The final answer should be .6380. I don't believe we need to subtract anything from 1. Does this make sense?
Oh, I see what you are saying now. Yes, we could think of it as two separate inequalities a greater than and a less than, "X4.5." But it gets tricky when we need both of them to be true.
Any time you see one like 4.5< X
Very helpful ! Thanks
Good job boss. Please, is there anything we could do together
And what if I'm not sitting in front of a binomial table. How do I work it out without one?
Some calculators can do it too. What kind of calculator do you have?
@@AndyMath Fx-82 au plus II
@@ashleyl7608 I looked around online and I can't find any tutorials for your calculator to do this. I know a lot of graphing calculators can do it, but as far as I can tell online, yours doesn't. I could be wrong. If you have a computer, you can google "z-table" and it should provide plenty of them you can use. I hope this helps!
@@AndyMath Thanks for the help.
Thanks, what about fb-82ESPLUS calculator?
You make it so easy, thanks
What table are you use?
what if we can't use the z-table and we have to find the probability
This was so helpful thank you so much now I can pass my test!!
I am so happy to hear. Let me know if you have any other questions!
Example two i have got a different value. First my table only reads up to 0.5 so i have to split the area, 0.5 plus the the other area. i dont know where i am missing out coz i have repeated twice and still got 0.5517.
thank you , really helped me
I am so happy to hear. Let me know if you have any other math questions. I'll see if I can answer them.
What if you dont have a z table?
He's been 22 for 8 years now
Thank you so much
how to find mean when standard deviation and probability is given??n excel
Thank you!!!
Hi Andy !
Great help!
Hello. Thank you for this video. What is the question asks the probability of selecting a score between the mean and a score of 90. If the mean is 80 and standard deviation is 10?
it would be similar to the steps in number 3 and number4 in the video. Except P(80
understandable.
I might sound stupid here but where can I get the z table cause I goggled it and there were a lot of different ones which one am I supposed to use.
www.z-table.com/
I just googled it too, this one seems nice.
@@AndyMath OK thank you so much for your quick response sir now I can get on with my assignment.
@@dflash1019 Great. Write anytime with math questions, I am happy to help. You can subscribe to find me easily.
@@AndyMath Yes I have subscribed any questions I face I'll be sure to let you know
my stats teacher has us add or subtract .5 based on the problem. what is the difference between that and what you do
The add or subtract .5 is probably related to a Continuity Correction. It is the adjustment made when a discrete distribution is approximated by a continuous distribution. If you were using the normal distribution to approximate some other distribution, then you would need to use the +/-.5. Hopefully this helps, if not, let me know and I can try to explain further.
Thank you so much 🤩
thanks
Why did he minus one in the second sum
The z table always returns the area less than the point. Since question number 2 asked for greater than (>) you want to subtract it from 1. If you do 1- the area less than. It give you the area greater than. I hope this makes sense!
I dont really know how to solve this..I hope someone can help me answer these problems😊
Mean is 72 with standard deviation of 12, find
A. Proportion above 90
B. Proportion below 90
C. Proportion between 48 and 95
D. Proportion between 75 and 85
E. Proportion above 55
Thank you in advance❤️😊
Thanks for during to me
thx
thank you so much!!!!!!
Wow. 👍
I realize on the Z table you skip the first number?
yes, as the first number on the table would be the 0. so if you’re looking at, say 1.3, that first number would be 1.30. then 1.31, 1.32, 1.33 and so on.
A god
thank u
I am happy to hear it helped. Let me know if you ever have any other math questions.
You love to see it
wow i just learned what a z table is 2 days before my exam lol why coudnt my prof just do this
Same lmao
Why are stat profs so bad
Sir what if there are ≤ signs as well
Hi. Since it is a continuous distribution, everything is the same for ≤ signs as < signs.
A great help Sir. I owe you one. Tomorrow is my Statistics Exam, nd this was the only topic left. But now its done just because of you.
@@ranasingh8913Thank you for the kind message. Good luck on your test! If you ever need more math practice, I put together a website andymath.com that organizes all my math notes. It's free, I like people to use it!
Okay Sir thanks a lot
Oh great
Please someone help me! 😂 I have a problem that is not horrible but my teacher has me so confused!
the fuck is that table