A museum surveyed three groups of 5 members to find out how many times the members visited the museum in the past year. This table shows the results of the three samples. Survey Visits to the Museum
Group 1 {4, 10, 6, 3, 8}
Group 2 {3, 1, 2, 1, 2}
Group 3 {7, 9, 3, 4, 7}
Identify any surveys that are likely biased. Based on the unbiased surveys, estimate the mean number of visits per member in the past year.

Enter your answer in the box. Round to the nearest whole number.

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.

br tat so much r

your answer is c. y = [x] + 1