i think that the question has some problems here. Like
KarishmaB was saying a linear relationship might be negative or positive (depending on the sign of the angular coefficient of the line)
infact i answered E. and i'm pretty sure that should be the right answer
| forecast | actual |
| march | 16 | a |
| april | 20 | b |
is
a-b <0?
statement 1 x= 12 clearly not sufficient
statement 2 we know that
unit sold = K * unit forecasted + Q
now we know that plugging the number in the table
a = K * 16 + Q
b = K * 20 + Q
let's make the difference between the 2 equations, we get:
a-b = K * 16 - K * 20 =
-4*Kthus a-b will be greater than zero if K<0 (negative relationship)
and a-b will be less than zero if K>0 (positive relationship)
THUS it is not sufficient.
statement 1 and 2 together do not help in any way. INFACT the only thing that taking both together is doing, is giving us a POINT (the actual and forecasted values in MARCH) on a LINE (the linear relationship). and we know that
through a
point pass a
INFINITE number of LINES. thus neither both statement together can be used to check if the relation is positive or negative.
answer E IMOBunuel, can you please check if my line of reasoning makes sense?