Line of best fit (Edexcel GCSE Statistics): Flashcards
📚Flashcards
Practise the cards
7 cards from this deck
ShowHide
Practise the cards
7 cards from this deck
Why extend the line beyond the data?
Why extend the line beyond the data?
To allow predictions outside the data range
How to read y when x is known on graph?
How to read y when x is known on graph?
Draw vertical to line, then horizontal to axis
Formula for mean point with frequencies?
Formula for mean point with frequencies?
x̄=Σfx/Σf and ȳ=Σfy/Σf
How to judge a good line of best fit?
How to judge a good line of best fit?
Approximately equal points above and below line
Is a line valid if it misses the mean point?
Is a line valid if it misses the mean point?
No. It must pass through the mean point (x̄,ȳ)
From y=-2x+10, estimate x when y=4
From y=-2x+10, estimate x when y=4
x = 3
Must line pass through origin if mean point isn't (0,0)?
Must line pass through origin if mean point isn't (0,0)?
No — it must pass through the mean point (x̄,ȳ).