1. Consider n pairs of numbers (x, y),(X, Y),..., and (xy). The mean and standard deviation of the x-values are x =5 and sx = 4, respectively. The mean and standard deviation of the y-values
are ý = 10 and sy = 10 respectively. Of the following, which could be the least squares
regression line?
A) Û = -5.0 + 3.0x
B) 9 = 3.0x
C) 7 = 5.0 + 2,5x
D) 9 = 8.5+ 0.3
E) y = 10.0 +0.40

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.

493 would be the correct answer

step-by-step explanation: