The Student Room Group

2 questions biverate data

for the first photo question 4 I don't know why this isn't a reasonable statement. my guess would be who would have a house with no rooms? but I guess there's an actual mathematical answer behind it

for the second photo question d. I plotted the data in a scatter graph found the outlier. I found the fair price using regression line but how do i comment on the validity what does this mean IMG_20190101_201335-compressed.jpg.jpeg

IMG_20190101_201349-compressed.jpg.jpeg
Reply 1
Original post by utv
for the first photo question 4 I don't know why this isn't a reasonable statement. my guess would be who would have a house with no rooms? but I guess there's an actual mathematical answer behind it

for the second photo question d. I plotted the data in a scatter graph found the outlier. I found the fair price using regression line but how do i comment on the validity what does this mean IMG_20190101_201335-compressed.jpg.jpeg

IMG_20190101_201349-compressed.jpg.jpeg


For your first question 4) your answer is reasonble, the data would only have examples with 1, 2, 3, 4, ... bedrooms. If you interpreted the constant as a house with no bedrooms, you'd be extrapolating the model outside the data. Extrapolation is often poor.

For the 2nd question, which brand is overpriced? It must be D. I would presume that the model is too simple, D could be some form of luxury brand for which the percentage choclate isn't enough to represent this?
(edited 5 years ago)
Reply 2
when commenting on validity on question d chocolate question do you talk about it being more suitable to use the regression line equation rather then my own line for validity or is this incorrect
Reply 3
Original post by utv
when commenting on validity on question d chocolate question do you talk about it being more suitable to use the regression line equation rather then my own line for validity or is this incorrect


I'm not sure what you're asking, you're given the regression line, you don't have to work out your own?
Reply 4
for part b it says he uses the line to find the fair price and then d it asks you to comment on the validity of his method . I guess what im confused on is the actual question . validity is that how accurate it is?
Reply 5
Original post by utv
for part b it says he uses the line to find the fair price and then d it asks you to comment on the validity of his method . I guess what im confused on is the actual question . validity is that how accurate it is?


From the sketch on the scatter plot, I'm presuming its ok, but you've not posted that picture and I've not worked it out. For d), I'm presuming they want you to think about why an outlier may occur. In this case its in the middle and overpriced. It could be a luxury handmade chocolate, and this factor would not be included in the model if it was just based on %cocoa?

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