A clothing store purchases T-shirts for $4.00 each and then marks up the price
of each by 55%. What is the markup and
new price of each T-shirt?

The mark up is $2.20 and the new price of each T-shirt is $6.20.

Step-by-step explanation:

Before we find the new price of each T-shirt we must find the markup (by how much were raising the price).

The problem states each T-shirt costs $4.00, but then marks up the price of each by 55%.

Step 1 would be to find 55% of $4.00.

0.55 * 4 = 2.2

So that is the mark up, the price is going up by $2.20. To find the new price of each T-shirt, you take that $2.20 and add it to the original $4.00.

$4.00 + $2.20 = $6.20

So the mark up is $2.20 and the new price of each T-shirt is $6.20.

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.