In marissa's calculus course, attendance counts for 1515% of the grade, quizzes count for 2020% of the grade, exams count for 5050% of the grade, and the final exam counts for 1515% of the grade. marissa had a 100100% average for attendance, 8989% for quizzes, 8686% for exams, and 8181% on the final. determine marissa's course average.

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.

5   1/4   miles per hour

step-by-step explanation:

15   3/4 / 3 = 5   1/4