Coding mean and standard deviation.

have you tried - 20?

I have been given a coding problem by my tutor which I cannot get my head around.

Ben played 19 games of basketball. Here are the points he scored in each game:
(26, 17, 19, 20, 18, 23, 23, 20, 18, 28, 23, 18, 29, 22, 25, 12, 22, 15, 26)

By using a code value of 20, work out the mean score for Ben. All workings must be shown.

All the problems we have solved so far have provided an equation for the code value not a whole number.
In my attempt I just used it as +20, so mean would increase from 21.263 to 41.263. I presume this is wrong however as that seems far too easy.

Any help would be so greatly appreciated.

Thanks in advance.

It may help to see the original question (pls post and it sounds like edexcel exam?), but you generally do a transformation to make it easier to calculate a mean, then do the inverse transformation of your result to get the actual mean. Youve had examples in the past, so you must have done something like that? The data is obviously clustered around 20.

Having said that, if its from your tutor, maybe raise the query with them to confirm what theyre asking?

Thank you for the feedback. My tutor is unfortunately proving difficult to contact and I just want to get the assignment out of the way. I have added a photo of the question and have tried to find it from past papers but to no avail.



I can wait for an answer from my tutor, I was just so stumped and frustrated.
(I’ve covered my workings out because they are irrelevant)

Why do you use code values? If you understand that you pretty much know the way to do the problem, even if the code value was not given.
As your tutor gave you the question, they must be the person who knows your work the best and therefore can give you the most appropriate advice, especially as its an exam question. If you can post the link to the publically available question, I will provide a bit more advice.

Unfortunately that’s all I have been given, just one sheet of paper. And the only teaching resource was mathswatch. Where the code was always supplied as a y= equation and I’m not sure how to then relate that to a whole number..

It’s A-level questions but part of an access to medicine course. I will just have to contact him and admit defeat.

No harm in asking him for a hint/advice if you can't get started? In fact, its better he recognises this as an area to give you further help. If your only learning is examples in mathswatch for which you're not sure of the purpose, you should be explicitly asking him about this.

There are examples in youtube (Ive just googled), it must be in your textbook, ... There is hardly a lack of information about topics like this.

I will speak to him regarding everything.

Please could you point me in the right direction re youtube as in my eyes and if i follow my textbook and say that y= 20 I still don't know how that would relate to Y bar and thus the mean is just +20 - I'm presuming this is wrong.