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Q&A DQ Courses
#1

I do not understand this answer, may someone help?

My Code:

row_1 = ['Facebook', 0.0, 'USD', 2974676, 3.5]
row_2 = ['Instagram', 0.0, 'USD', 2161558, 4.5]
row_3 = ['Clash of Clans', 0.0, 'USD', 2130805, 4.5]
row_4 = ['Temple Run', 0.0, 'USD', 1724546, 4.5]
row_5 = ['Pandora - Music & Radio', 0.0, 'USD', 1126879, 4.0]

fb_rating_data = row_1[0]
insta_rating_data = row_2[0]
pandora_rating_data = row_5[0]

row_1[0] = row_1[4] 
row_2[0] = row_2[4]
row_5[0] = row_5[4] 
avg_rating = (row_1[0] + row_2[0] + row_5[0])/3

What the system expected to happen:

row_1 = ['Facebook', 0.0, 'USD', 2974676, 3.5]
row_2 = ['Instagram', 0.0, 'USD', 2161558, 4.5]
row_3 = ['Clash of Clans', 0.0, 'USD', 2130805, 4.5]
row_4 = ['Temple Run', 0.0, 'USD', 1724546, 4.5]
row_5 = ['Pandora - Music & Radio', 0.0, 'USD', 1126879, 4.0]
fb_rating_data = [row_1[0], row_1[3], row_1[-1]]
insta_rating_data = [row_2[0], row_2[3], row_2[4]]
pandora_rating_data = [row_5[0], row_5[3], row_5[4]]


avg_rating = (fb_rating_data[2] + insta_rating_data[2] + pandora_rating_data[2]) / 3

Instructions: For Facebook, Instagram, and Pandora — Music & Radio, isolate the rating data in separate lists. Each list should contain the name of the app, the rating count, and the user rating. Don’t forget that indexing starts at 0.

For Facebook, assign the list to a variable named fb_rating_data.
For Instagram, assign the list to a variable named insta_rating_data.
For Pandora — Music & Radio, assign the list to a variable named pandora_rating_data.
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.
Assign the result to a variable named avg_rating.
As a side note, we could calculate the average rating here a little bit better using the weighted mean — we’ll learn about the weighted mean in the statistics courses.

#2

Hi,
Your logic with average in the end of your code is right, but you could do the same exactly after first block of lists.
What you did’t do:
For Facebook, assign the list to a variable named fb_rating_data.
For Instagram, assign the list to a variable named insta_rating_data.
For Pandora — Music & Radio, assign the list to a variable named

Generally you need not only to count average, but also clean, filter and make your easy for reading

This block makes new lists with easy to read names , and less rows, excluded price and ‘usd’. At the same time you took only 3 lists from 5 in intial block of lists.
Next step to count average from this new named lists.

Hope , I could help you

#3

Thank you. This was a good feedback.