was this a valid for a half mark? (1 Viewer)

[anonymoushehe]

we got our tasks back for maths adv and one of the questions was a simple finding the linear regression line equation - y = Bx + A. The question said something alone the lines "find the linear regression line where B and A are integers" — but the thing is, when you calculate A and B the values are actually weird decimal values that aren't integers and everyone in the class thought that the exact values of A and B (not rounded) shouldve been integers, so everyone lost half a mark? But apparently the teacher said you were meant to round it to the nearest integer - is this even valid cause the wording seemed misleading. It wouldve made more sense if said "find the values of A and B to two decimal places" or smth

 

[Average Boreduser]

we got our tasks back for maths adv and one of the questions was a simple finding the linear regression line equation - y = Bx + A. The question said something alone the lines "find the linear regression line where B and A are integers" — but the thing is, when you calculate A and B the values are actually weird decimal values that aren't integers and everyone in the class thought that the exact values of A and B (not rounded) shouldve been integers, so everyone lost half a mark? But apparently the teacher said you were meant to round it to the nearest integer - is this even valid cause the wording seemed misleading. It wouldve made more sense if said "find the values of A and B to two decimal places" or smth

I agree. The wording does not suggest any rounding was required.

 

[Hehehe22]

Yeah me too, if it's not an integer then it's not an integer. If they want you to round then they need to say so

 

[Tony Stark]

Tell your teacher that for an answer to inherently be an integer, the equation that produces such an integer must equal to that integer with no further approximations (i.e x=y, not x≈y).

The equation from the question clearly gave a non-integer (a float) and thus an approximation would need to be made to align with the marking guidelines. This is called rounding, whereby the rounded number (the integer that was asked for) is not exactly equal to the output from the equation (i.e x≈y).


This definitive condition therefore depicts the unjustified question and mark, because an integer was not possible, but a rounded approximation to 0 decimal places was.

Logically speaking, if I tried converting a non-integer number to an integer, I would not be able to.

import math

x = 1.618
y = int(x) #outputs an error
#print(y)
y = round(x, 0)
print(y)

 

[Study to success]

they give half marks in math? My school hasn't been giving half marks ever since year 10 cause apparently in the hsc they don't