Confused by text "Total Number of ratings" simple v weighted average

The text “and then divide the total by the number of ratings.” caused some slight confusion on my part - I created another variable to sum the total ratings, to get a weighted average, instead of a simple average as required.


Hi @AcB,

Welcome to the community! You are right. It should use the weighted average method. However, since this is a beginner level mission, we excluded the concept as the focus was on teaching about lists and for loops in python.

I believe we can add a note in that mission screen that talks about the weighted average, which they will learn in the stats missions. I will get it logged.


Hi Sahil,

Thank you - I’m enjoying it!
I think if the text said " and then divide by 3" it might be enough to keep users thinking about a simple average. However I leave it in your hands!

It may be as I’m new, however I think it would be cool if the greyed out “312-4” number above my first comment could link back to the course screen so that we can return after future comments easily.

It’s nice to know you are reviewing the comments.

Thank you


Thank you for the suggestion! I will let the content team know about it.

Great suggestion! I am not sure about the feasibility of it. However, here is a workaround to visit the mission screen link using the 312-4 tag. The first number 312 is the mission number and the second number 4 is the screen number.

Just replace the mission_number and screen_number in the above url using the numbers in the tag like this:

Hope this helps :slightly_smiling_face:


Hi ,
Although the mission includes an information regarding “weighted average” , the goal of this mission is still confusing for a beginner.
Maybe a line like “You’ll need to add the ratings together first, and then divide the total by the number of rating data list created.” could be helpful.


For comparison, this is the original text in the mission:

"Compute the average user rating for Facebook, Instagram, and Pandora — Music & Radio using the data you stored in fb_rating_data, insta_rating_data, and pandora_rating_data.

You’ll need to add the ratings together first, and then divide the total by the number of ratings."

This seems very confusing to me because “the number of rating data list created” is 3 (three) because there are three “rating data lists”…namely: fb_rating_data, insta_rating_data, and pandora_rating_data.

Thanks for the reply.
I totally get your point, however i think the confusion stem from the fact that the term rating is used multiple times and associated either to user rating , rating count and rating data list.
Although in the mission original text it implies or refers to the number of rating data list.

However, if this is not raised by other users then the current wording is fine.


So very true! I will admit, I had to read it more than once to make sure I knew what was being asked of me. I found the word number caused me some confusion as well since the ratings themselves are just numbers. Maybe the word count would be better here? Dunno.

Now that we have expanded on this a bit further, I think the best over all solution to avoid confusion (if one, as you say, is actually needed) would be to use a quick simple example in order to illustrate that all we want is just a simple average/mean of the ratings being stored in three separate lists.

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I found this instruction to be confusing:

Compute the average user rating for Facebook, Instagram, and Pandora — Music & Radio using the data you stored in fb_rating_data , insta_rating_data , and pandora_rating_data .

Looking at the answer provided, it looks to be solving for the average NUMBER of user ratings for FB, IG, and Pandora - not the average user RATING itself…

Hi,I also confused in this instruction.Why we dont give all user ratings with negative indexing ?Here one of them is 4 and anothers are given as -1.Why?