Binomial Distribution: Using the Probability Tables

[@Gleb170785]

Thank you very much! That's been one of the best explanations of Statistics I've listened and watched so far! There's a very good proverb that many people try to teach us something but very few are worth to be called teacher. Your case is definetely the second one! Thanks!

[@MashrufKabir]

Amazing how you made it all so simple. Thank you so much! You saved a life here :)

[@ericratcliffe3716]

Thank you for such an eloquent and educating video!

[@NaveenKumarasinghe]

Thank you very much! It's a very clear explanation.

[@rhembe]

OMG, you saved my life. Thank you!!!!!

[@noorameera26]

Thank u very much! Awesome video, full of information!

[@danfuller5537]

Great video, helped a lot

[@springgbb]

OK that makes perfect sense! thank you!

[@TheBunnyming]

THIS IS SO HELPFUL ;_; THANK YOU.. you saved my exam today!

[@MrNichollTV]

Glad to be of help!

[@MrNichollTV]

Thank you very much!

[@kostong756]

This is a great video!!! Thank you so much...

[@MrNichollTV]

Thank you!

[@luissuarez1753]

great video cheers

[@MrNichollTV]

Thank you!

[@emanfederer2706]

Thank you so much

[@Gleb170785]

:) I'm a beginner in Statistics, to say the least and I understood that I had to mutiply 0.8 by itself 9 times. But actually I've got your result when I do the operation 8 times. And when i pressed multiplication key 9 times I had 0.1073742. 0.8 * 0.8 * 0.8 * 0.8 * 0.8 * 0.8 * 0.8 * 0.8 * 0.8 * 0*8 =

[@springgbb]

the values that i have in the table in my book are different, for example - when n = 15, successes = 4 and the probabilty = 0.3 my book reads 0.2186

[@haiderkhan23]

how can I interpolate suppose I have p=.03 at x=0 n=10

[@Gleb170785]

i would only like to ask you one thing. I either didn't find the proper value in the table or calculated something wrongly. If I have the probability 0.20, sample of 10 and the probability that exactly one unit is defective wich is P (X=1) right?. In the table i found 0.2684, in my calculations 0.2147

[@MrNichollTV]

You can only use the table if the probability of success is a multiple of 0.05. If it is 0.39, then you would need to use the formula to work out an accurate probability.

[@musfiqurrahman4576]

Thanks a lot lot lotzzzzzzzz

[@MrNichollTV]

Aha! Now I see what has happened. When you press the key once you are working out 0.8 * 0.8 = 0.8^2 and when you press the key 9 times you are working out 0.8^10. The power is one greater than the number of times you press the key, because you start with 0.8^1 before pressing the key at all. Good luck with your Statistics!

[@Gleb170785]

well, in my calculations 0.8^9 = 0.1073742, 10 * 0.2^1 = 2 . and 2 * 0.1073742=0.2147. Please tell what I do wrong.

[@MrNichollTV]

If you have p= 0.03 and n = 10, I would use the formula to calculate the correct probabilities. No need for interpolation!

[@MrNichollTV]

My calculator says 0.8^9 = 0.134217728 and 0.8^10 = 0.1073742. How did you work out 0.8^9?

[@alankota797]

How would I use that table if my probability of success is 0.39?

[@MrNichollTV]

I think you have made an error using the formula. The calculation should be 10 * 0.2^1 * 0.8^9, which is 0.2684 to 4 decimal places, as you worked out from the table. I think that you have accidentally typed 10 * 0.2^1 * 0.8^10 as that gives 0.2147.

[@noway4879]

your C table looks different than mine ... how is this possible?

[@noway4879]

Because yours are already added up !!! You ought to explain this before the video, I almost went into the exam thinking there were different C-tables, which of course is impossible.

[@MrNichollTV]

I am Alucard Sorry for any confusion. My table is the one from the Edexcel formula booklet. You are quite right that this is a table of cumulative probabilities.

[@MrNichollTV]

Your book is not wrong but it is tabulating a different thing. Your book is giving probabilities whereas most formula books give cumulative probabilities. So in this case your book is giving the chance that X = 4 whereas the A-Level formula book gives the chance that X is less than or equal to 4. The reason that most books give cumulative probabilities is that it makes it easy to find the probability of a range of outcomes; individual probabilities can calculated quickly with the formula.

[@HotmailHacks]

16 minutes?! no one has time for that!!